Fiction expands not necessarily from getting readers to spend more money on books, but by bringing in more new reader / buyers. (whatever.scalzi.com)
The game's developers have implemented a system where players get rewarded for bringing in new people, so it isn't difficult to acquire a free copy of the game. (gameluster.com)
Both need to pay tax, both look for low risk high growth strategies, and both will (hopefully) have a purpose that goes beyond bringing in $ $ $. (money.stackexchange.com)