Immersive Labs has some demos set up at SXSW and I found one on the 3rd floor of the convention center.
Their technology analyzes the audience of a video screen and serves up video content based on the composition of that audience. In this case it identified me as a young adult male and started showing me a PepsiCo reel. It can also take into account factors such as weather (which is lousy right now) and geolocation.
I don’t know how they figured out that I drink a lot of Pepsi though, that part was a bit uncanny.