Product Placement is a way to get your product seen without using traditional advertising. I think product placement could be used for market research too. Imagine an online game that doesn’t offer only Coca-Cola (product placement), but offers lots of drinks. You could then correlate the choice of drinks with demographic information you have about your gamers—age, gender, income, and so on. By watching activities within the game, you could correlate the choice of drinks with MUD personality types (Killers, Achievers, Socializers, Explorers); this might tell you what kinds of magazines you want to advertise in. You could see whether people who hang out together are more likely to drink the same sorts of drinks (energy boosters, soda, water, juices, etc.). You could pay some people to switch drinks and see whether others follow. You can measure correlations between products (do people who drink Red Bull also eat hamburgers?).
Does this creep you out? It should (unless you work in marketing). Product placement is what we have now, but I think in the future we’ll have people using virtual worlds as a way to run experiments on us. In virtual worlds you can measure behavior better. There is of course the question of whether product choice and behavior in the virtual world differs from the physical world, but having detailed data about a million players can complement having sparse data about a few thousand survey participants. Given that games—unlike movies—let players choose what to do, product placement in games seems like a waste. Market research seems to me to be a much more valuable way to use that opportunity.