It doesn't say it didn't (that I can see). I think it's saying AIM brought the concept into the mainstream, and I think that's probably more or less true in the US.
Interestingly (to me, at least), this seemed to be pretty reasonable. No one I knew in Canada had AIM, except if they talked to Americans regularly. MSNM was very very popular, though. And ICQ before it.
Yeah, you needed aim if you wanted to chat with some americans when I played utopia. Meanwhile the big IM breakthrough among my less technical friends was msn. I quite quickly found a stand along multi-protocol client and I've stuck to that mode of managing IM since when I could control it.
