It reminds me a little of when that analyst was digging around in AT&T wireless filings and stumbled across some numbers that suggested the kindle was selling a lot back then.
I love kindles. I love Amazon. But in a rational world, we wouldn't be arguing about whether e-books and/or kindle e-books were an "impressive" portion of overall book sales. We'd be having a really serious discussion about how we feel about a probable effective monopoly on a par with what Wintel had with personal computers for a lot longer than they should have.
Maybe we feel like that's a good thing. There's an argument to be made for standardization. And there are a few people talking about it. Heck, maybe it wouldn't make any difference one way or another in the long run anyway.