Yes. Amazon itself is undoubtedly data mining your purchase history, but at least they're not spewing your personal info to every random Serfville/PirateWars "games" that one of your friends signs up for (yes, I know that you can turn most of that off, and I have; most people don't).
Everything I've heard and experienced indicates that Amazon is pretty tight with customer information. Certainly you don't get any personal information on customers when you sell ebooks through the Kindle store. Apple is also pretty good about that.
