Before Diddy was a spokesperson for Pro-Activ, there was this promotional tape about the prescription anti-acne cream Retin-A: the Retin-A rap: [videoembed size="full_width" alignment="center"][/videoembed] I like how the first half of the video (and the rap) are about how great Retin-A was, and the second half is about how you shouldn't give up even when the side effects are terrible. ...