Twitter banned third-party ad networks after people had put a lot of work (and $5M of funding, in Ad.ly's case) into third-party ad networks.
And Facebook tried to screw over Zynga when they saw how much money they could be making if they forced Zynga to give them a cut by using Facebook's currency. Besides for that, they've been very good to developers. But that's a pretty egregious offense.
And Facebook tried to screw over Zynga when they saw how much money they could be making if they forced Zynga to give them a cut by using Facebook's currency. Besides for that, they've been very good to developers. But that's a pretty egregious offense.