Kindle as a platform, not a device
I haven't used the application yet (will do later when I get back home), but there are a couple of things of importance about this release that I would like to point out:
1.- By Amazon releasing this software on the iPhone, they are converting the Kindle into platform more than just the device. this is important as you most likely have Amazon releasing this App for more devices (other cell phones, other e-readers?, PCs, etc). If you don't the Kindle device, you will still have access to their platform on the device of your liking. What Amazon wants is to sell books to as wide an audience as possible. This is the second step (the first was the Kindle device itself)
I've been reading that newspapers and magazines are not working on the iPhone. While this is an issue, it is only temporary as publishers will most likely push Amazon to correct this and have access to a wider audience.
2.- Hearst Publishing was reported to be developing their own reading device to compete against Amazon and keep some of the profits from the book sales. This move from Amazon puts it way ahead of them and others (you hear me Sony reader?) in the same way that Apple did when they introduced the iPhone.
First, was the revolutionary device (iPhone in June 2007), then the pervasive ecosystem (App Store, in July 2008). Now everybody in the mobile industry is running to catch up. Once you start buying from within the ecosystem (App Store, Kindle store) you are attached to it. And the more you buy, the more attached and dependent you are.
This is a very good business move.
I mention, I haven't used the software yet, and I may have my own quibbles of usability with it. But good thing about software, it can always improve. But having access to 240,000 books so easily makes it a very tempting offer to refuse.