You might think that an official, legalese statement makes your policy sound more formal and ironclad. But you're wrong. Gibberish does not create trust. Of course, there's no way to really prove that you follow your own policy. This fact is tough on everyone.
Consumers know that it's all just words on the screen.
Retailers can't show that they are, indeed, honest. The ones that are dishonest, meanwhile, can make a killing selling private data to others and the honest retailers can't easily expose such a betrayal. The whole area of policing privacy policies is a black hole. A few watchdog and security groups do a privacy audit every now and then, in an attempt to embarrass the really big sites. It works, too.