This was covered about a month ago in a topic on this forum... use the Search function to find it. The basic answer is, no, not really. GiftCertificates.com used to sell Amazon certificates, so you could have earned miles by buying certs. They no longer offer Amazon certs, so now USAir is the only way, and even that isn't really reliable.

FYI, Amazon has specific rules for its affiliates that they CANNOT provide rewards for shopping with Amazon. That's why it's hard or impossible to find these rewards unless you go a roundabout way (like gift certificates).