Another problem that is likely to contribute to spam is that it is quite easy to create bogus accounts for the Ping service because no credit card or other positive identification is required to participate.

FORBES: Apple's Ping Plagued By Spammers

Apple said Friday it has signed up more than one million users for the Ping music discovery service the company launched Wednesday.

FORBES: Apple Says Ping Has More Than One Million Users

And some iTunes initiatives, like a Ping social networking service, flopped.

WSJ: Eddy Cue: Apple's Rising Mr. Fix-It