Sony has patented a new form of trial or demo for video games that, rather than presenting us with a small piece of a title, gives us the whole thing, then takes bits away as time goes on.
After playing a demo for a certain amount of time, or having completed a set number of turns or actions, the product would begin to gradually remove content, eventually compelling the consumer to buy the game in order to keep playing. The above picture, in which a player's weapons are downgraded, does a pretty good job of displaying this.
Another scenario is the one below, in which a driving game's tracks are removed one by one.
It's... well, it's a great idea. Provided the means to bypass the degradation routines aren't easily or commonly broken, it's a much better way for developers and publishers to let people experience their product than current demo limitations allow.
Of course, it would also mean 10-40GB downloads instead of 1GB ones, but included is the possibility of returning the demo to physical media, so that's one feasible option.
Sony Patents Degradable Video Game Demos [Siliconera]