Yglesias has an even more sinister theory: that there's no real rhyme or reason to Amazon's strategy, that it's acting on the assumption that having beaten the market into submission there will somehow, in some way, be a way for Amazon to capitalize on the resulting chaos --- but that it's equally likely that Amazon will itself crater, having destroyed everyone's profits in the process.
I like Amazon (we're Prime subscribers), but I have to bear that in mind every time I prepare myself to complain about Wal Mart (which I do not like).
In any case: it's close to impossible for a small-scale retailer to compete with Amazon once Amazon decides it's competing.