This article at AlterNet, Hold the Applause for Amazon.com is worth reading. There's a lot of discussion in the mystery community about Amazon, but Jeff Milchen takes a slightly different slant, analyzing the enterprise more from a business perspective.

The "revolutionary" company lost billions of dollars -- an average of $376 million annually during its first eight years -- yet it kept enticing speculators to pump more money into the company's stock. Amazon's speculation-fueled growth contributed to the net loss of more than 2,000 independent book and music sellers during its first decade.

It is probably fair to say that Amazon has had an effect on the publishing industry far out of proportion to the numbers of books it sells. (The article notes that Independent book sellers still account for 10% of sales as opposed to 7% for Amazon)

Amazon has certainly taken a grip on authors' minds. Even though I've learned that Amazon numbers have little relation to overall sales, I check the sales rankings for our books endlessly. The fluctuations are, after all, evidence that something's happening, someone's paying attention. It's on demand cyber applause.