Amazon is buying books for $13, and selling them for $9.99.

Donald Marron has an interesting post about Amazon's negotiations with book publishers.  The gist of it is whether Amazon's policy of buying electronic books for $13 and selling them for $9.99 is good for the industry.  In the short run, at least, publishers sell more books at higher prices.  The long-run potential cost of this practice is that Amazon becomes the "platform" or "essential facility" of choice for buyers and sellers of books.  Currently it sells 80% of online books.