It took Amazon (amzn) less than a month after the release of the second-generation Kindle electronic-book reader to put a free Kindle application on the iPhone App Store. It took another two months for it to fix the app's second most annoying drawback (after the iPhone's tiny screen): the hoops you had to jump through to buy new titles.
Amazon solved that problem Monday morning by launching a Kindle store "optimized" for the iPhone. Before if you wanted to buy a book for the iPhone, you had to get it from your Kindle (if you had one), or from Amazon via a computer, or from Amazon's site as viewed through the iPhone's browser -- not a user-friendly experience.
Now iPhone users can buy directly from within the Kindle application through a new interface that works like an iPhone app should and doesn't require a magnifying glass.
It's no mystery why Amazon keeps showing the iPhone its love. The company hasn't released sales figures for either the Kindle 1 and the Kindle 2, but according to press reports, it has probably sold 700,000 to 800,000 of the devices in their first 18 months.
Apple (aapl), by contrast, has sold some 37 million iPhones and iPod touches.
And since Amazon CEO Jeff Bezos has made it clear that he is far more interested in selling e-books than he is in selling Kindles, it makes sense for him to put his content on as many devices as he can -- and to make reading that content as seamless as possible.
At the launch of the Kindle 2, Amazon VP Ian Freed said that the company was working hard to bring Kindle apps to a variety of existing smartphones, starting with the ones that offer the best reading experience.
UPDATE: iLounge's Charles Starrett points out that there could be a small wrinkle in the Apple-Amazon relationship: By selling its e-books directly to readers, Amazon may have found a way to avoid the 30% cut Apple will start taking this summer when it opens the App Store to so-called " in-app purchasing."
The new Kindle store, writes Starrett, "appears to be a workaround to enable easy purchasing without Apple revenue sharing."