FR3085518A1 - CONTENT DISPLAY METHOD AND SYSTEM - Google Patents

Abstract

Method for displaying contents of advertising campaigns on display devices (2, 3) in a closed environment in which members of the public can move along paths between entry / exit points (30, 33), the method including: - defining all the possible paths, - determining the display devices which are visible from each path, - determining an average flow of people traveling on each path, - receiving campaign data comprising a display calendar and a target audience, - allocate a specific set of display devices to the advertising campaign to reach the target audience.

Description

Content display method and system.

TECHNICAL AREA

This communication relates to methods and systems for displaying content, in particular advertising.

More particularly, the present description relates to the methods and systems for displaying content on specific display devices chosen from an inventory of display devices, as a function of characteristics of advertising campaigns. “Inventory of display devices” means a set of display devices that can be used to display the content of poster campaigns.

TECHNOLOGICAL BACKGROUND

Document WO2009 / 144459 describes a method for assigning content to specific display devices chosen from an inventory of display devices.

OBJECTS

An object of the present description is a computer-implemented method for displaying content of advertising campaigns on display devices i belonging to an inventory of display devices, i being an index designating the display device, said inventory being arranged in a closed environment in which members of the public can move along a certain number of paths between entry / exit points, the method including:

- define all the possible paths p between the entry / exit points, where p are indices designating the paths respectively,

- for each path p, determine the display devices i of the inventory which are visible to the people traveling on said path in each direction AD,

- determining for each path p and each direction AD, an average flow of people PAX _{P; AD} (t) traversing said path p, where t is time,

- receive on at least one allocation server, campaign data from a specific advertising campaign c, said campaign data comprising at least one display calendar and a target audience,

- allocate to the specific advertising campaign c, by said at least allocation server, a specific set of display devices i of the inventory and a display chronology on each display device i of the specific set display devices so that an audience affected by the specific campaign displayed on the specific set of display devices i with the specific display chronology corresponds to the target audience, said affected audience being determined as a function of the specific set of display devices i, the specific display chronology and the average flows of people PAX _p , _AD (t) on the paths p from which each display device i of the set is visible specific display devices,

- send the content corresponding to the specific advertising campaign c to the specific set of display devices i.

In the embodiments of the above method, one or more of the following characteristics may also be used, as well as any of their combinations:

- said closed environment is a space for access to a means of transport and the average flow of people

PAXp, _AD (t) are average passenger flows;

- said closed environment belongs to at least one airport (it may for example consist of one or more passenger terminals of said at least one airport);

- The method further comprises determining for each display device i of the inventory, an average exposure time DEi during which the display device i is visible to people traveling at least one of the paths p, and it is determined said audience also affected as a function of the duration of exposure DEi specific to each display device i;

- Said average flows of people PAX _p , _AD (t) are expressed in average numbers of people PAX _p , _AD (dj) traveling each path p during successive time ranges dj, where j is an index designating the time range;

- said audience affected by the specific campaign c on each display device i of the specific set of display devices is expressed in number of OTS eye contact opportunities _c , i (dj) of people with said specific campaign c during all the time periods dj corresponding to the display calendar for the specific campaign;

- said number of OTS eye contact opportunities _c , i (dj) is calculated in the form:

OTS _c , i (dj) = ^ i ^ -NCDEJ.PAXp ^ Cdj) (1) p

or :

“I and 5i are coefficients specific to the display device i, respectively representative of the residence time of people in certain areas or of the presence of additional people not counted in the PAX _{P; AD} (dj) flows,

N (DEi) is a number of times that each person is likely to see the display device i, depending on the average duration of exposure DEi, and

P is the set of paths p from which the display device i is visible;

- N (DEi) is calculated by the formula:

N (DEi) = C (DEi). SOT _c , i (dj) (2) where:

C (DEi) is a function coefficient of DE _± , and

SOT _{C; i} (dj) is the proportion of time during which the specific campaign c is visible on the display device i during the time range dj;

- the display device i is configured to display the specific campaign c for slots of duration DS and the coefficient C (DEi) is calculated by the formula:

C (DEj) = 1 + ^DE '~ ^2X (3)

DS where X is a minimum contact time between a content and a person to consider a contact, that is to say to consider that the person really had the opportunity to see this content;

- said audience affected by the specific campaign c on each display device i of the specific set of display devices is expressed in number of effective eye contacts V _c , i (dj) of people with said specific campaign c during all the time ranges dj corresponding to the display calendar for the specific campaign;

- The number of effective eye contacts V _{C; i} (dj) is calculated by the formula:

V _{C; i} (dj) = 3i.OTS _c , i (dj) (4) where βί is a non-zero real number between 0 and 1, specific to the display device i;

- Said closed environment is subdivided into zones to which the display devices i belong and the coefficient cq depends on the zone to which the display device i belongs;

- each path p is defined by at least one intermediate point between two entry / exit points;

- each path p is defined by a single intermediate point between two entry / exit points;

said inventory of display devices comprises digital display devices each containing at least one electronic screen and a reader adapted to display the contents on said screen, and the step of sending the contents corresponding to the advertising campaign specific c to the specific set of display devices i, includes:

electronically send said content and the corresponding chronology to the respective readers of the digital display devices forming part of the specific set of display devices, memorize said content and said chronologies by said readers and have said content displayed according to said chronology on said screens;

the step of allocating to the specific advertising campaign c, by said at least allocation server, a specific set of display devices i of the inventory and a display chronology on each display device i of the specific set of display devices, is performed by at least one artificial intelligence module;

- Said artificial intelligence module includes at least one neural network.

The present description also relates to a system comprising:

an inventory of display devices i, i being an index designating the display device, said inventory being arranged in a closed environment in which members of the public can move along a certain number of paths between entry points / output, and at least one computer configured to:

- define all the possible paths p between the entry / exit points, where p are indices designating the paths respectively,

- for each path p, determine the display devices i of the inventory which are visible to the people traveling on said path in each direction AD,

- determine for each path p and each direction AD, an average flow of people PAX _p , _A D (t) traversing said path p, where t is time,

- receive campaign data from a specific advertising campaign c, said campaign data comprising at least one display calendar and a target audience,

- allocate to the specific advertising campaign c, a specific set of display devices i of the inventory and a display chronology on each display device i of the specific set of display devices so that an audience affected by the specific campaign displayed on the specific set of display devices i with the specific display chronology corresponds to the target audience, said audience affected being determined as a function of the specific set of display devices i, the specific display chronology and the average flows of people PAX _{P; AD} (t) on the paths p from which each display device i of the specific set of display devices is visible,

- send the content corresponding to the specific advertising campaign c to the specific set of display devices i.

In the embodiments of the system, one or more of the following characteristics can also be used, as well as any of their combinations:

- said closed environment is an access space to a means of transport;

- said closed environment belongs to at least one airport (it may for example consist of one or more passenger terminals of said at least one airport);

- said at least one computer is further configured to:

determine for each display device i of the inventory, an average duration of exposure DEi during which the display device i is visible to people traveling on at least one of the paths p, and determine said audience affected in addition according to the exposure time DEi specific to each display device i;

- said flows of people PAX _{P; AD} (t) are expressed in average numbers of people PAX _{P; AD} (dj) traveling each path p during periods j is an index designating 1s

- said specific audience c on each specific set of successive time periods dj, or time range;

affected by the display device campaign i of display devices is expressed in number of OTS eye contact opportunities _c , i (dj) of people with said specific campaign c during all the time periods dj corresponding to the display calendar specific campaign;

said at least one computer is further configured to calculate said number of OTS _c , i (dj) eye contact opportunities in the form:

OTS _c , i (dj) = ^ i- ^ i-NCDEJ.PAXp ^ Cdj) (1) p

or :

“I and 5i are coefficients specific to the display device i, respectively representative of the residence time of people in certain areas or of the presence of additional people not counted in the PAX _{P; AD} (dj) flows,

N (DEi) is a number of times that each person is likely to see the display device i, depending on the average duration of exposure DEi, and

P is the set of paths p from which the display device i is visible;

- said at least one computer is further configured to calculate N (DEi) by the formula:

N (DEi) = C (DEi) · SOT _c , i (dj) (2) where:

C (DEi) is a function coefficient of DEi, and

SOT _c , i (dj) is the proportion of time during which the specific campaign c is visible on the display device i during the time range dj;

the display device i is configured to display the specific campaign c for slots of duration DS and said at least one computer is also configured to calculate the coefficient C (DEi) by the formula:

C (DEi) = 1Æ — VL · (3)

DS where X is a minimum contact time between a content and a person to consider a contact, that is to say to consider that the person really had the opportunity to see this content;

- said audience affected by the specific campaign c on each display device i of the specific set of display devices is expressed in number of effective eye contacts V _{C; i} (dj) of people with said specific campaign c during all the time ranges dj corresponding to the display calendar for the specific campaign;

- The number of effective eye contacts V _{C; i} (dj) is calculated by the formula:

Vc, i (dj) = 3i.OTS _c , i (dj) (4) where βι is a non-zero real number between 0 and

1, specific to the display device i;

- Said closed environment is subdivided into zones to which the display devices i belong and the coefficient depends on the zone to which the display device i belongs;

- each path p is defined by at least one intermediate point between two entry / exit points;

- each path p is defined by a single intermediate point between two entry / exit points;

- said inventory of display devices comprises digital display devices each containing at least one electronic screen and a reader adapted to display the contents on said screen, and said at least one computer is further configured to send electronically said content and the chronology corresponding to the respective readers of the digital display devices forming part of the specific set of display devices, each reader being adapted for:

memorizing said content and said chronologies and displaying said content according to said chronology on said screens;

- Said at least one computer comprises at least one allocation server comprising at least one artificial intelligence module trained to optimally allocate to the specific advertising campaign c, a specific set of display devices i of the inventory and a display chronology on each display device i of the specific set of display devices;

- Said artificial intelligence module includes at least one neural network.

BRIEF DESCRIPTION OF THE DRAWINGS

Other characteristics and advantages will appear in the light of the following description of an embodiment, given by way of non-limiting example, with reference to the accompanying drawings.

In the drawings:

FIG. 1 schematically shows part of a system for displaying content in a closed environment,

FIG. 2 is a block diagram of the system of FIG. 1,

FIG. 3 is a block diagram showing some of the software components of the system of FIG. 1,

- Figure 4 is a diagram showing a neural network usable in the system of Figures 1 to 3 for the allocation of display devices to a campaign;

FIG. 5 illustrates the functioning of the neural network of FIG. 4.

DESCRIPTION MORE

DETAILED

In the different drawings, the same references designate identical or similar elements.

Figure 1 shows a system 1 for displaying content on display devices 2, 3, in a closed environment, in which members of the public can move in a number of ways between entry / exit points 30 , 33.

The closed environment in question may in particular include a space for access to a means of transport such as a station, an airport or the like. It can also be a shopping center. The following description will be made in the case of an airport or a group of airports, but it applies equally to any other closed environment.

The screens 2 may possibly be of several types. The different types of displays can correspond to different formats or different designs and to different types of media such as digital or “paper” media.

At least some (advantageously all) of the display devices can be digital display devices 2.

As illustrated in FIG. 2, the digital display devices 2 (D FR) can include a reader 2a (that is to say a computer with a processor and a mass memory) controlling an electronic screen 2b such as a LED or LCD electronic screen, or any other known type of electronically addressable screen. The content played by reader 2a can be images, films, web pages or any other type of digital content which can be displayed on the electronic screen 2b.

The display devices 3 with paper poster (P FR) can be backlit or not, with fixed or mobile posters and the posters can be sheets of paper or any suitable synthetic sheet.

The system 1 can comprise at least one allocation server 4 (SERV 1), for example a plurality of allocation servers 4.

Said allocation server 4 is programmed to receive campaign data relating to advertising campaigns and to assign to each advertising campaign, display devices 2, 3 (hereinafter "specific set of display devices") and a display chronology on said specific set of display devices (in particular display time slots (uniform or according to the display devices), frequency

display depending beaches hours and / or in function of devices display, etc.). The data from countryside can to be received especially from computer workstations 5 used through

the dedicated operators to system 1 (OPE), of posts of computer work 6 used through customers (CLT) or of a auction system in time real 7 (RTB). Once the server allocation 4 a allocated at

a specific advertising campaign said specific set of display devices 2, 3 and a display chronology on these display devices, the identification of the allocated display devices and the allocated chronology can be sent by said at least an allocation server 4 to at least one operating server 8 (SERV 3) which can, immediately or later, send (or have sent) the contents and the chronologies to the display devices 2, 3. The contents can be received on the operating server 8 from the allocation server 4 or from any other external source.

In the case of digital display devices 2, the contents and the chronologies can be sent to the readers 2a by a network 9 (N), local or wide.

In the case of paper display devices 3, the content is sent by operators who physically go to the site to change the posters.

Said at least one allocation server 4 can also communicate with one or more additional servers 11 (SERV 2), for example at least one additional server 11 adapted to train an artificial intelligence executed on said at least one allocation server 4 , as will be explained later.

As illustrated in FIG. 3, said at least one allocation server 4 can execute software called allocation module 12 which is configured to allocate display devices and display chronologies on these devices to advertising campaigns. 'display.

The allocation module 12 can communicate with the operator stations 5 using interface software (INT), with customer stations 6 via an API interface 14 and with the real-time auction system 7 thanks to a specific software interface 15 (EXCH) allowing automatic data exchange, for example under the "Open RTB" protocol.

When said at least one allocation server 4 is composed of a plurality of allocation servers 4, the allocation module 12 can possibly be executed simultaneously on all the allocation servers 4 of said plurality to improve the speed.

Display device inventory data may be contained in an inventory database. Optionally, said at least one allocation server 4 can have a random access memory (RAM) in which said inventory database is fully loaded in the form of objects as objects modeled with bit mask to improve speed. The inventory database may contain at least individual data of display type, location, availability and data on the audience of the display devices 2, 3.

The display type data can for example include data such as:

- the canal: for example "airport", "large format" or "street furniture",

- the type of media: for example digital, paper, digital and paper,

- format: display format,

- etc.

The location data may include the position of the display in the above-mentioned closed environment.

More particularly, the location data can be linked to the possible paths between the inputs / outputs 30, 33 of the closed environment considered.

To this end, all possible paths p are defined in advance between the entry / exit points 30, 33, where p are indices designating the paths respectively. In the case of an airport, the entry / exit points 30, 33 may in particular be doors 30 (E1, E2) leading to the outside and doors 33 (Gl, G2) for access to aircraft.

The paths p in question may possibly be defined in a simplified manner, each by two entry / exit points 30, 33 and an intermediate point 31 (S) corresponding for example to the security control zone.

Optionally each path p could be defined by more than one intermediate point between two entry / exit points, for example two intermediate points 31 (S), 32 (G), or more.

Each path p can have two directions AD (direction of departure and direction of arrival) or more (one can define, for example, specific directions followed by people in transit, accompanying persons, etc.). For a large airport, the number of such paths can be very high, for example more than 10,000.

In the simplified diagram of FIG. 1, there are 4 paths p if the paths are defined by a single intermediate point 31:

1. El-34-36-S-B-37 + 38-39-40-G1,

2. El-34-36-S-B-37 + 38-39-41-G2,

3. E2-35-36-S-B-37 + 38-39-40-G1,

4. E2-35-36-S-B-37 + 38-39-41-G2.

On the same simplified diagram of FIG. 1, there are 8 paths p if the paths are defined by two intermediate points 31, 32:

1. El-34-36-S-B-37-39-40-G1,

2. El-34-36-S-B-38-39-40-G1,

3. El-34-36-S-B-37-39-41-G2,

4. El-34-36-S-B-38-39-41-G2,

5. E2-35-36-S-B-37-39-40-G1,

6. E2-35-36-S-B-38-39-40-G1,

7. E2-35-36-S-B-37-39-41-G2,

8. E2-35-36-S-B-38-39-41-G2.

Each display device 2, 3 (P1-P5) can be defined with respect to the paths p from which it is visible.

Availability data can include the share of time (SOT, in%) already allocated of the display device (i.e. the share of time already spent on advertising campaigns) for each day and each period of the day and the references of the corresponding advertising campaigns. Each day can be divided into a number of periods, which can be allocated separately. These time periods may or may not be the same length. A non-limiting example of such time periods is:

period 1 : 6h - • 10h; period 2 : Oh - 4 p.m .; period 3 : 4 p.m. - 7 p.m .; period 4 : 7 p.m. - 6h.

For display devices 3 on paper with fixed posters, the time allocated to an advertising campaign will be 100% or 0 and will be the same for all time periods for a certain number of days.

For 3 paper displays with scrollable or otherwise movable posters, the share of time allocated to an advertising campaign will generally be a predetermined value (eg 25% for a roll display of 4 posters that are displayed sequentially) or 0 and will be the same for all time periods for a certain number of days.

The audience data can include, for each path p, for each calendar day and each period of time, for example an average flow of people (in particular travelers) PAX _{P; AD} (t) traveling along said path p, where t is time, said average flows of people PAX _{P; AD} (t) can be expressed in average numbers of people PAX _{P; AD} (dj) traveling each path p during successive time ranges dj, where j is an index designating the time range . The time ranges in question may correspond to the calendar days and time periods mentioned above.

Audience data can be broken down by several client segments (age, sex, nationality, socio-professional category, etc.) and / or include data allowing the audience's appetite for certain products or services to be known ( e.g. cigarettes, perfumes, etc.). In general, audience data contains all the data used to quantify and qualify the people exposed to a display device.

The average flow of people can be calculated for example from the total average flow of people in the airport or in an airport terminal, which is distributed between the different paths in proportion to a weight assigned to each path p. The weights of the different paths p are representative of the average proportion of people using each path p among the people using the airport or terminal considered.

The weights of the different paths can be determined once and for all or from time to time, notably by statistical observations of the behavior of the public at the airport.

The total number of people using the airport or a terminal can be determined on the basis of general airport attendance statistics and / or current data related to flight reservations. By using flight reservation data, it is thus possible to define average flows of people hour by hour for example.

The method of determining the flow of people described above is not limiting. As a variant and / or in addition, the flows of people can be determined or adjusted by measurements of permanent or temporary flow measurement sensors, or by using or modeling mobility data (from mobile phones or other).

The audience data can also include, for each display device i in the inventory, an average exposure time DEi during which the display device i is visible to people traveling on at least one of the paths p. These average exposure times can be determined in advance, once and for all, or revised from time to time. A typical exposure time DEi can be of the order of 40 s.

The audience data may also include coefficients cg and δ ± specific to each display device i or specific to an area in which the display device i is located (for example recording / reception areas at the exit of flight, commercial area, boarding area, baggage claim area).

The coefficient δ ± is representative of the residence time of people in these areas: it represents the number of passages of people within sight of the display device i. . The coefficient δ ± can for example be equal to 1 in transit areas and greater than 1 in areas where people remain relatively static.

The coefficient cg is representative of the presence of accompanying persons (check-in / reception areas at the end of the flight) or of persons employed by the airport. The coefficient cg is only useful when the above-mentioned average flows PAX _{P; AD} (t) only include passenger flows. If these average flows PAX _{P; AD} (t) include all the people, cg can simply be equal to 1.

The coefficients cg and 5i can be determined once and for all or from time to time, in particular by statistical observations of the behavior of the public at the airport.

For each new advertising campaign c to be processed, the allocation module 12 receives campaign data from the specific advertising campaign c, said campaign data comprising at least one display calendar and a target audience, and it allocates to the specific advertising campaign c, a specific set of display devices i of the inventory and a chronology of display on each display device i of the specific set of display devices so that an audience reached by the specific campaign displayed on the specific set of display devices i with the specific display chronology corresponds to the target audience.

The audience affected is determined by the allocation module 12 as a function of the specific set of display devices i, the specific display chronology and the average flows of people PAX _p , _AD (t) on the paths. p from which each display device i of the specific set of display devices is visible.

The allocation module 12 further determines said audience affected as a function of the exposure time DEi specific to each display device i.

Said audience affected by the specific campaign c on each display device i of the specific set of display devices can be expressed as the number of OTS eye contact opportunities _c , i (dj) of people with said specific campaign c during all the time periods dj corresponding to the display calendar for the specific campaign.

Said number of OTS eye contact opportunities _c , i (dj) can be calculated by the allocation module 12 in the form:

OTS _c , i (dj) = Xai ^ .NCOEij.FA ^ ADCdj) (1)

P where:

N (DEi) is a number of times that each person is likely to see the display device i, depending on the average duration of exposure DE _± , and

P is the set of paths p from which the display device i is visible.

N (DEi) can for example be calculated by the allocation module 12 by the formula:

N (DEi) = C (DEi). SOT _c , i (dj) (2) where:

C (DEi) is a function coefficient of DEi, and

SOT _c , i (dj) is the proportion of time during which the specific campaign c is visible on the display device i during the time range dj.

The display devices i can be configured to display the specific campaign c during slots of duration DS in a cyclical manner, in cycles of duration DL. In this case, the coefficient C (DEi) can be calculated by the allocation module 12 by the formula:

C (DEj) = l + ^{DE 1} ~ ^2X (3)

DS where X is a minimum contact time between a content and a person to consider a contact, i.e. to consider that the person has really had the possibility of seeing this content (X can for example be of the order of 1 second).

The audience can also be represented by a parameter V _{C; i} (dj) indicator of effective contacts, ie of the number of times that the content of the campaign has actually been seen. This parameter V _{C; i} (dj) can for example be obtained by the formula:

V _c , _i (dj) = p _i .OTS _c , _i (dj) (4) where βί is a non-zero real number between 0 and 1, specific to the display device i. βι can for example be determined once and for all or from time to time, in particular by statistical observations of the behavior of the public at the airport.

All demographics and audiences can be broken down by categories of people.

The distribution module 12 can be an artificial intelligence module trained to optimally allocate display devices and display chronologies to advertising campaigns.

Said artificial intelligence module can be trained by automatic learning (by supervised or unsupervised learning, and in particular “machine learning”) and more specifically by reinforcement learning, for example in deferred time, in a training module 16 (TRN) which operates on the additional server 11.

The training module 16 can be programmed to create a large number of artificially generated advertising campaigns (“synthetic campaigns”) and to train the artificial intelligence module on these artificially generated campaigns, which allows faster and more effective learning. .

In one embodiment, the artificial intelligence module can comprise a neural network 17.

For example, a particularly advantageous application is shown in Figures 4 and 5, where the neural network 17 has two layers, 19, 20 of sigmoid neurons.

More particularly, the neural network 17 can have:

- several inputs connected to the input nodes 22-26 in an input layer 18 (there are 5 inputs and input nodes in the example of Figures 4-5, but this number can vary from one mode of achievement to another),

the first layer 19 of the sigmoid neurons, having a certain number of sigmoid neurons 27 (for example 7 sigmoid neurons 27) each connected to each input node 22-26,

the second layer 20 of the sigmoid neurons, having a certain number of sigmoid neurons 28 (for example 3 sigmoid neurons 28) each connected to each sigmoid neuron 27,

an output layer 21, for example having an output node 29 connected to all the sigmoid neurons 28.

Neural network 17 can have a learning rate of 0.1 and a Gamma value of 1, for example.

When the allocation module 12 includes a two-layer neural network such as that of FIGS. 4-5, its operation can be as follows:

the first layer 19 successively scans all the devices for displaying the inventory for each period of time and calculates a vote representative of the audience thus allocated to the campaign c, and

- the second layer 20 determines the chronology (time share SOT in the time period considered) allocated to the advertising campaign c.

The first layer 19 is supplied by the input layer 18, receiving for each display device and each period of time scanned:

- a first input relating to the target audience,

- second input data relating to the cumulative audience volume of the display devices and the chronology already allocated to the specific campaign c,

- a third (optional) input data relating to the chronology already allocated to other advertising campaigns on a display device being scanned,

a fourth input data item relating to the total audience attainable by the display device being scanned, and

- a fifth input data (optional) relating to the width / height ratio of the display device being scanned.

All input and output data can be normalized digits between 0 and 1.

The above allocation process is very fast, usually around 1 to a few ms.

Claims (11)

1. Computer-implemented method for displaying contents of advertising campaigns on display devices i (2, 3) belonging to an inventory of display devices, i being an index designating the display device (2 , 3), said inventory being arranged in a closed environment in which members of the public can move along a certain number of paths between entry / exit points (30, 33), the method including: - define all the possible paths p between the entry / exit points (30, 33), where p are indices designating the paths respectively, - for each path p, determine the display devices i (2, 3) of the inventory which are visible to people traveling on said path in each direction AD, - determining for each path p and each direction AD, an average flow of people PAX _P , _AÜ (t) traversing said path p, where t is the time, - receive on at least one allocation server (4), campaign data from a specific advertising campaign c, said campaign data comprising at least one display calendar and a target audience, - allocate to the specific advertising campaign c, by said at least allocation server, a specific set of display devices i (2, 3) of the inventory and a display chronology on each display device i (2, 3) of the specific set of display devices so that an audience affected by the specific campaign displayed on the specific set of display devices i with the specific display chronology corresponds to the audience target, said affected audience being determined as a function of the specific set of display devices i, of the specific display chronology and of the average flows of people PAX _PfAD (t) on the paths p from which each device is visible display i of the specific set of display devices, - send the content corresponding to the specific advertising campaign c to the specific set of display devices i, in which said inventory of display devices (2) comprises digital display devices each comprising at least one electronic screen (2b) and a reader (2a) adapted to display the contents on said electronic screen (2b), and the step of sending the contents corresponding to the specific advertising campaign c to the specific set of display devices i (2), includes: electronically sending said content and the corresponding chronology to the respective readers (2a) of the digital display devices forming part of the specific set of display devices, memorizing said content and said chronologies by said readers (2a) and. display said content according to said chronology on said electronic screens (2b). 2. Method according to claim 1, wherein said closed environment is an access space to a means of transport. 3. Method according to claim 1 or claim 2, further comprising determining for each display device i (2, 3) of the inventory, an average duration of exposure DEi during which the display device i ( 2, 3) is visible to people on at least one of the paths p _f and said audience affected is further determined as a function of the duration 5 of exposure DEi specific to each display device i. 4. Method according to claim 3, in which said average flows of people PAX _p , _AD (t) are expressed in average numbers of people PAX _PfAD (dj) traveling each path p during successive time ranges 0 dj, where j is a index designating the time range, said audience affected by the specific campaign c on each display device i of the specific set of display devices is expressed in number 5 of OTS eye contact opportunities _c , i (dj) of people with said specific campaign c during all the time periods dj corresponding to the display calendar for the specific campaign, and said number of ocular contact opportunities 0 OTS _c , i (dj) is calculated in the form: OTS _c , i (dj) =, X (DE) .PAXp _{> AD} (dj) (1) P where: ai and δι are coefficients specific to the display device i, respectively representative of the residence time of people in certain zones or of the presence of additional people not counted in the PAX flows _p , _ad (dj), N (DEi) is a number of times that each person is likely to see the display device i, depending on the average duration of exposure DEi, and P is the set of paths p from which the display device i is visible. 5. Method according to claim 4, in which N (DEi) is calculated by the formula: N (DE _i ) = C (DE _i ). SOT _{C; i} (dj) (2) where: C (DEi) is a function coefficient of DEi, and SOT _c , i (dj) is the proportion of time during which the specific campaign c is visible on the display device i during the time range dj. 6. Method according to claim 5, in which the display device i (2) is configured to display the specific campaign c for slots of duration DS and the coefficient C (DEi) is calculated by the formula: u (DEj) = 1 + ---------- i ----------------- (c) DS where X is a minimum contact time between a content and a person to consider that the person really had the opportunity to see this content. 7. Method according to any one of claims 4 to 6, in which said audience affected by the specific campaign c on each display device (2, 3) i of the specific set of display devices is expressed in number of effective eye contacts V _c , i (dj) of people with said specific campaign c during all the time periods dj corresponding to the display calendar of the specific campaign, and the number of effective eye contacts V _Cf i (dj) is calculated by the formula: V _Cf i (dj) = βί. OTS _C , i (dj) (4) where βι is a non-zero real number between 0 and in leauel said ironr 2 8 is subdivided into zones to which the display devices i belong and the coefficient oq depends on the zone to which the display device i belongs 9. Method according to any one of the preceding claims, in which each path p is defined by at least one intermediate point between two entry / exit points. 10. Method according to any one of the preceding claims, in which the step of allocating to the specific advertising campaign c, by said at least allocation server (4), a specific set of display devices i of the inventory and a display chronology on each display device i of the specific set of display devices is carried out by at least one artificial intelligence module (12). 11. System comprising: an inventory of display devices i (2, 3), i being an index designating the display device, said inventory being arranged in a closed environment in which members of the public can move along a certain number of paths between input / output points (30, 33), said inventory of display devices (2) comprises digital display devices each comprising at least one electronic screen (2b) and a reader (2a) adapted to display the contained on said electronic screen (2b), and at least one computer (4, 8, 11) configured to: - define all the possible paths p between the entry / exit points (30, 33), where p are indices designating the paths respectively, - courtyard chaaue path p, determine the display devices i of the inventory which are visible to people traveling on said path in each direction AD, - determining for each path p and each direction AD, an average flow of people PAX _PfAD (t) traversing said path p, where t is the time, - receive campaign data from a specific advertising campaign c, said campaign data comprising at least one display calendar and a target audience, - allocate to the specific advertising campaign c, a specific set of display devices i of the inventory and a display chronology on each display device i of the specific set of display devices so that an audience affected by the specific campaign displayed on the specific set of display devices i with the specific display chronology corresponds to the target audience, said audience affected being determined as a function of the specific set of display devices i, the specific display chronology and the average flows of people PAX _PfAD (t) on the paths p from which each display device i is visible from the specific set of display devices, - electronically send said content and the corresponding chronology to the respective readers (2a) of the digital display devices (2b) forming part of the specific set of display devices, said respective readers (2a) of the display devices; digital displays forming part of the specific set of display devices being adapted to store said content and said chronologies, and to display said content according to said chronology on said electronic screens (2b)