[Sofa King]

"What about video games? How much money are you going to make selling Doom T-shirts?"

Well, one thing that the video game industry has is multi-player. You need a CD-key (a 20 digit code that is unique to each copy of the game) to play the game on their servers, and since multiplayer is the big draw, people will have to buy the game.

[longtermmemmory]

there are random key generator programs