You really should watch this slideshow at Gizmodo titled Amazon: The Hidden Empire. I suspect you'll be surprised by how much of your internet life passes through Amazon's kingdom.

And I think that slideshow is a nice dispute to the rumor going around that Amazon is considering buying Borders. If they do so well at controlling customer experiences on the internet, why would they want to get into brick-and-mortar retailing at this late date? The variables are multitudinous, and Amazon has no experience with physical bookselling. (And with a failed company like Borders, Amazon would want to rethink the whole operation from the floor on up.) I think they're way more likely to choose to expand even further into our internet lives, especially with the upcoming Amazon tablet (that may actually be two Amazon tablets).