I did no user testing (just did what I thought was obvious), I only had 3 months, I worked by myself (mostly), and my site, http://like.fm, doesn't suffer from most of his fail points. I think apple just wanted to add a slight social layer to their store.. You know, to drive sales. I mean if you are one to buy stuff from the iTunes store, you'll probably sign up and follow something. Other people who use the service aren't immediately going to be much value. I mean why else would they make a "social network" embedded in iTunes. You just can't expect something like that to get enough meaningful adoption if it's exclusive to a single platform in a heavily segmented market. So apple wasn't crazy (they just can't be that blind), they just wanted to add a light social layer to iTunes store to boost sales.