Amazon wants to get his nose into the coins of the users, so you can already see how things will work if Amazon ever accepts Bitcoin, they will attempt to track everything and sell your information, just like Facebook.
They can only sell their transaction logs and information of their customers who uses it, but IMO they would not succeed in tracking everything since it is very easy to create a new wallet to use when transacting with amazon. The only problem is the user's address and other personal information that they can sell. I hope they wouldn't resort to it.