When Apple launched Ping  in September, it was expected - in some quarters - to revolutionize music discovery. Representing the optimism at the time, Wired bravely deemed it "too big to fail"  and immediately declared it a social powerhouse-in-waiting. Too big to fail... of course, that's what people used to say about the U.S. banking system before the fall of 2008.
A social network layer for the iTunes music store, Ping allows users to follow both friends and artists. When a friend buys or "likes" a track or album, Ping alerts his social network. Similarly, an artist's Ping followers get status updates for events like shared videos or new songs available for purchase at iTunes.
But Ping has been slow to catch on. It has added artist profiles at glacial pace. Users' activity feeds appear barren compared to the constant chatter in Facebook and Twitter. And although Sony used Ping to launch a new Michael Jackson song, it has lacked the kind of attention-grabbing moments an online service needs to gain traction.
The numbers don't lie. Consider the case of Alison Krauss and Union Station. Earlier this week the group released a new video clip announcing the April 12th release of its "Paper Airplanes" album. The 34-second preview clip was posted to Ping on Wednesday afternoon and had received 28 "likes" 24 hours later. The same video was posted at Facebook  Tuesday afternoon and amassed 1,494 "likes" over two days.
Granted, the Facebook post had the advantage of the extra day, but Facebook's 52-fold lead over Ping has little to do with timing and everything to do with user activity. The large difference between the two hints at Facebook's dominance in creating conversation and awareness for music artists. If the Facebook "likes" didn't attract attention in those 1,493 social networks, the 211 comments the Alison Krauss video generated may have had an impact. In contrast, Ping users left only 7 comments.
A video post by British electronic band the Prodigy was met with a similar disparity. The January 8 Facebook post  had generated 5,249 "likes" and 411 comments by Thursday afternoon. At Ping, the same video was posted on January 12. By Thursday it had just 53 "likes" and 13 comments.
The disparity in "likes" and comments goes far beyond the difference in number of users. When Ping launched, Apple said iTunes had 160 million users. Facebook had somewhere around 500 million users, giving it a roughly 3-to-1 lead. But Facebook outperformed Ping 52-to-1 in the Alison Krauss video and 98-to-1 for the Prodigy video.
While Facebook is the place people spend time with friends, iTunes appears to be the place where music fans buy and listen - and little else.
Why has Ping failed to impress thus far? For one, it encompasses only a sliver of what a typical social network offers. You can't share a wide variety of items on Ping like you can on Facebook. Second, iTunes added in a social layer without fundamentally changing iTunes to be more social. iTunes users are still within a walled garden (even though they can invite their Facebook friends to join Ping). Thus, it misses what has made Facebook so successful: it's where everybody goes to hang out. Third, Ping captures only part of the online word of mouth involved with digital music. People like to share links to videos, web pages and webcaster channels - none of which need involve iTunes.
All up these three factors and you get a media player and store that does not lend itself toward social activity. That could very well change over time as Apple releases future iterations of both Ping and iTunes. But for now there's little indication that Ping is on a path to become a social juggernaut.