Well the only chance now, as I see it, is Kobo. If they're going to pick up the Barnes and Noble business then that will strengthen their position. Currently I buy ebooks from both Kobo and Amazon, but as I have a Sony reader I have to convert the Amazon books I buy which is a bit of a pain (incidentally that Sony is now 8 years old and still going strong), so my preference is Kobo, both morally (I've never had the sort of problems some have described with Kobo and really don't like Amazon's dominance and proprietary format) and for convenience, however I have to buy Amazon for self publishing authors who only put their books on Amazon and then, of course, I must convert them. I will also buy from Amazon when they are significantly cheaper than Kobo but that is becoming very rare now. Kobo do seem to have made an effort to take Amazon on at their own game and they are now mostly the same price and sometimes cheaper.