Game publishers are always looking for new ways to provide that "first free hit" as if they were nerdy drug dealers, and a fresh patent from Sony appears to have stumbled upon an interesting way of doing it. The filing details a "degradable demo" that provides users with a full game, and then slowly strips away features until the player is forced to buy it.
The detailed software lets a developer set when the game downgrades. For instance, a powerful sword could become weaker and weaker over a set number of hours, levels might disappear from the game, or the sound and graphics can weaken in quality. Fiendish.
Sounds positively evil, but it would likely have a brilliant effect. Thus the psychological war between publisher and consumer continues.
Sony Patents Degradable Video Game Demos [Siliconera]