And they should. They get the best deal as far as i can tell compared to Fictionwise where I get most of my ebooks. And though Fictionwise has done a lot to make sure that their prices are more competitive since Kindle has been out, it's still difficult to pay about 30% more for the same book as folks would on Amazon's Kindle.
And there's definitely a market for it. Now, iPhone users appreciate having eReader as an app and now Stanza has more to offer readers but having more competitors is always good for mobile warriors. And let's not forget that the iPhone is only a minority in the smartphone market (even though it's not a smartphone).
There is Android where Amazon is the default music seller. Let's not forget the millions and millions of Blackberries and Windows Mobile devices. Palm folks already discovered eReader and would also appreciate Kindle compatible reading materials.
Let's hope some folks over at Amazon will do some math on this and see that volume speaks, well, volumes. And Amazon should continue to innovate Kindle. A lot of the revenues from selling books on other mobile platforms can only add to the bottomline and maybe even help lower Kindle's retail prices and the search and development that went into it.
And if Amazon is afraid people will stop buying Kindle, let me tell you this. You've got a nice dedicated reader in Kindle with a bigger screen than smartphones and most mobile devices. In time you'll also be lowering the price point for Kindle. People will flock to it as long as you give mobile readers a reason to buy it.