What I think the author misses is how short lived these monopolies can be. AOL was a near monopoly. So was Netscape. And Internet Explorer. So was Altavista. Or was it Excite? Or Yahoo? Was it Nintendo that had the gaming console monopoly or Sega? Wasn't there a great Scandanavian monopoly on phones? Until there wasn't.

Companies can lock down their market for a generation, or perhaps half a generation, but few hold onto it forever.