Earlier this year, Amazon (somewhat quietly) introduced its . By adding Android apps to its existing online retail empire of digital books, music, movies, and television, Amazon set the stage for the introduction of its own tablet hardware.

Hardware and store integration are not new concepts for Amazon. The company led the e-reader market for so long because, in large part, of its tight integration with Amazon.com. Tight integration between tablet (and phone and media player) and the iTunes Store is what propelled Apple to its sales summits. Amazon certainly must be hoping it can build on the success of its Kindle devices by creating its own, tightly integrated shopping, buying, and consuming experience on an Android tablet.

Presumably, this will be an experience that's more organic than the one you get by shopping at Amazon today on an Android tablet, using the various Amazon apps. And it will presumably leverage the breadth of selection and attention to customer experience and other details that a retail Goliath like Amazon can provide.

Other tablet makers are trying to integrate their own branded digital stores too, Acer and Toshiba among them. And meanwhile, Google is chasing both Apple and Amazon with its own Android Market services, which for now include selling apps and books, and renting movies.

It's obvious that Amazon knows how to sell (the company logged $9.86 billion in sales in the first quarter of the year). All the company needs is a competitive platform to integrate its shopping and playback experiences. That will be the raison d'etre for any forthcoming tablet.