I think it was their lack of vertical integration that did it. there were too many pieces that every developer needed to do, that made it really hard to make apps for it. compare that to the app store where Apple just takes a 30% cut, which is steep, but they do things for that 30%. On the consumer end of things, the actually affordable data plan with att at launch, which is more vertical integration, rather than letting the carriers do their thing, is what did it, imo.