Currently, they're taking a loss on many/most/all (?) of these $10 ebooks.
Unproven. I submit they're taking a loss on NONE of the e-books you can purchase there. Figure it this way: go onto any e-publisher's web site and you will see e-books sold for $5, $6, $7...this is what the publisher feels the book is worth to the consumer, and offers the house a modest profit.
Now you have Amazon charging $10 for pretty much everything, when they have no upfront costs as do the publishers, and claiming they cannot make money on the titles?
Please. I don't think so. Despite Med's statement that they have their digital "stocking" charges to pay and certain other overheads, most of those are a one-time charge against any individual title. Plus, Amazon benefits from every conceivable economy of scale. I feel they're being disingenuous when they whine they can't make any money.
What's really at stake here is that neither Amazon nor the publishers want the e-books to drain off hardcover and/or PB sales, so they price the e-versions artificially high. And they're making money. Depend upon it.