Some of the old games are… not designed to run on modern hardware. Call of Juarez, for example, runs very poorly (frame drops and crashes)

Ah, thanks! It seems like they just buy out the game, and they can give out unlimited licenses.

I feel like they have some sweet deals with publishers that only when people download a game for the first time does the license get activated. Or you just have an IOU license. Just a speculation tho.