This displays the robustness of an relatively unconstrained innovation ecosystem. Even near monopolies - and "sure things" - are subject to unanticipated, but

This displays the robustness of an relatively unconstrained innovation ecosystem. Even near monopolies - and "sure things" - are subject to unanticipated, but powerful emergence. As we worry about "monopolies" like Facebook, Twitter, and others, it's comforting to look to the past and see once-monopolies like AIM and Microsoft be challenged and overturned by upstarts. It bodes well for the future of our society that entrepreneurs can redirect the course of history by successfully challenging entrenched incumbents.