Yeah, but if one book makes Amazon more money than another book, I believe they are smart enough to prioritize that book. it can make more money in a couple of ways. One way is by costing more per book. Another way is by selling more copies. I believe their algorithm would take both of these scenarios into consideration when ranking. If it doesn't, it probably should. :)

Why do you say they are a data-collecting machine first and a business second? I think everything drives the business. Things that make them money become strategic to their business. Data collecting, product search, whatever.

I was very successful on elance for about 15 months. At one point I was ranked #3 out of 120,000+ programmers <Barney-Fife-Sniff>. Nominally a lot went into their rankings - number of reviews, average value of reviews, number of projects, number of acceptances per bid, etc etc. They made a lot of noise about all the things you could do to get a higher ranking. It was all BS. Their ranking was almost entirely derived from how much money you pumped through their system. At one point I secured a long term contract at $100/hr. So for like 6 months I had no other projects, just that one. No reviews. No bids. No nothing. But I billed my ass off and my ranking skyrocketed.

I have to believe profitability is taken into consideration with Amazon. Things that make them more money will be rewarded. Thought experiment: two books. Same niche. Same exact number of sales per day. Same everything. One book is $20, one book is $0.99. No way that $20 book is ranked lower than the $0.99. Amazon is too smart not to put that bad boy front and center!

I'm not sure if this is actionable information. Probably not useful at all...