Online advertising models are based on the collection and analysis of numerous behavioural traces: browsing data, interaction data (with the interface, content, other users, etc.) and online transaction data. The data collected depends, to a large extent, on the technologies used and the regulatory frameworks governing user privacy. For example, the introduction of smartphones, through the use of tactile and visual interfaces (touch screens, cameras, sensors), has already introduced the collection of data relating to users' bodies (fingerprints, facial recognition, physical activity), whether for non-monetised use (unlocking the phone or accessing applications through authentication) or monetised use (free service in exchange for access to data).

With the Metaverse, new advertising formats could be developed by capturing data linked to the use of a virtual/augmented/mixed reality headset and body movements. For example, it is possible to deduce certain emotions from data relating to eye movements, facial expressions, movements, or even voice intonation.

This could lead to an intensification of behavioural marketing, with the risk of "monetising our attention, gestures, and emotions in real-time", marking the culmination of a kind of "cognitive capitalism” [[[Report of the French exploratory mission on metaverses, p. 90]]].

What's more, since metaverses are based on spatialised experiences within three-dimensional digitised environments, it is not hard to imagine that the Metaverse's territories, ranging from the smallest parcel, or even the smallest pixel, to the largest space, could represent infinite possibilities for advertising, to the point of saturating vision and attention.

In virtual worlds, autonomous (i.e. programmed) agents can advertise in a variety of ways, for example by wearing branded clothing, or by tailoring a message (via text, voice, gestures, etc.) as soon as they detect a nearby user. In the Metaverse, and thanks to advances in artificial intelligence, a new digital version of the "sandwich man" could be born.

The author believes that “this is especially dangerous when the AI algorithms have access to data about our personal interests and beliefs, habits and temperament, all while monitoring our emotional state by reading our facial expressions and vocal inflections. If you think targeted ads in social media are manipulative, it’s nothing compared to the conversational agents that will engage us in the metaverse. They will pitch us more skilfully than any human salesperson, and it won’t just be to sell us gadgets – they will push political propaganda and targeted misinformation on behalf of the highest bidder [[[“The metaverse will be filled with ‘elves’”, Tech Crunch, 12 janvier 2022 : https://techcrunch.com/2022/01/12/the-metaverse-will-be-filled-with-elves/]]]

It is worth noting that this expansion of advertising models could be applied to individuals, not just autonomous agents. In addition, and as a result of these prospects, we may see the emergence of bypass strategies (such as ad blockers) or “premium” type economic models, which would allow this type of advertising to be removed in exchange for monetisation of the experience.