Personally, I've been playing alot more facebook games recently instead of playing wow.  Usually the business model is like this, "We'll let you pay for free, but if you want anything extra you'll pay for it."  Which is fine.  My strategy is to play many different games at once.  Then over time I build up my status rather then paying through the noose for things. 

It would be likened to a martial arts studio where the lessons were free but there was a payphone for students, there was coin operated machines to sell everything, there was coing operated showers, and gym lockers, etc.  Personally, I think some of this motion sensor technology would be very useful in martial arts studios.  For instance you could have a "Danger Room," where people rented out.  It would be a combination of a holodeck/treadmill. 

For example, the martial arts studio could also sell martial arts video games.  For example, there are alot of games that use motion capture technology.  This could be quite useful in martial arts training.