Since expansions were an enormous undertaking that usually saw itself released 9-12 months after the game, publishers needed something to hold the gamers interest until then.something more, but less than an expansion. By 90 days, these games were rarely played as the gamer had moved on to the next new appealing game.
I'm not sure what study I read, but after 60 days, it was noticed that the initial appeal of a new game wore off. Sadly, there is always someone/some company that is going to perverse the ingenuity of DLC As I remember it, the idea of DLC was the created to give the game more content to make the game appealing even after the initial 90-day release.
