Ask HN: What do you think are the possibilities of this app?

At some stage you have probably pondered on what to buy next on iTunes so you looked at the "most downloaded" lists etc. These lists are good but they aren’t the opinions that you value and trust the most!

With this app you select friends from Facebook which you think have good taste and only buy useful, interesting stuff on iTunes. We will then put their apps, music, movies and books into individual leader-boards so you can see what to buy next and make some useful discoveries!

I have been working on this idea and want to get opinions on it. Is this useful? Is the value proposition big enough for users to sign up (likely to be Facebook app)? Are there any features you would like to see?

Thanks for opinions.