Max runs down some reasons why he uses Amazon for his book links on The Millions. I don't want to rehash all his points, but I agree with all of them, and if this is something you think about, you should see what he says. Basically, this is the heart of the matter:
like many sites that affiliate with Amazon, has an editorial rather
than an "advertorial" mission, and one reason we link to Amazon is
because it offers the most information about the books we write about,
whether we recommend them or deplore them them. As long-time blogger Matthew Cheney put it recently, "I want a link to give you the most information and options with the fewest clicks."
To his list of reasons, I'll also add one more: reporting. Hands down, Amazon gives me the most information about how I'm doing as an affiliate. With Amazon I can get up-to-the-day sales info and also track it historically. I can know which links are working, how many people clicked what, how they got to the page (although everything is kept completely anonymous). This is a great source of info: for one thing, it has absolutely helped me fine-tune how I use links on this site. For another, I've discovered many new books this way. And it also lets me know when I've discussed books that people are excited about and when I've bored them.
By contrast, Powell's only gives me sales info, which in my opinion is the bare minimum that anyone offering an affiliate program should think of giving. Any less than that, however, and we have a problem. If you're leaving your affiliates in the dark as to something so basic as how much they're earning off your program, you're failing.
Unfortunately, by that measure IndieBound is failing. I recently added an IndieBound searchbox to give readers the alternative to buy books through IndieBound and still support this site and The Quarterly Conversation, but I am disappointed to say that I have completely no idea if 1 or 10 or 100,000 of you have bought a book through my searchbox. IndieBound offers no way to tell whatsoever. (If Amazon did this I can only imagine the consipracy theories of affiliate-cheating that would be on the Internet right now.)
I will grant IndieBound the fact that it's a new site and will possibly improve this in the future, but I sincerely hope that this functionality is in the works.