Maybe the quote of the day from osnews article
Of course, being a new social network, Ping is suffering from ghost town syndrome.[Like Google Wave i might add] One of my OSNews colleagues posted on Facebook that he couldn't find anyone to follow on Ping. (Keep waiting, dude!) Swizec notices that while he can "follow" Lady Gaga, who he doesn't like, none of the bands he actually does like are on Ping yet. And they never will be, because in two weeks everyone will have forgotten that Ping ever existed. It will be like that Quicktime desktop app or Safari for Windows that Apple installed on your computer when you activated your iPod: something you vaguely remember as having hitched a ride with iTunes.
And did i mentioned that is useless too ? it's just a sucky social network.
Instead of broadcasting to the world what music you, you know, actually like best and listen to, it only tells people what you bought or rated at the iTunes store.