What research firm Gartner describes as the $2.1 billion "personalization services" industry is known to everyone else as that unintelligible (is that Beyoncé?) sound coming from someone who didn't get the "your phone should always on vibrate" memo. Gartner predicts that in 2015 digital music revenue will hit $7.7 billion with ringtones still factoring into that figure. AllThingsD's Peter Kafka notes, "To sum up: More than 10 years after Napster, one of the key pillars of the music business is ringtones, a business that peaked around 2005,"  and adds:

And Gartner thinks ringtones won’t die off anytime soon — four years from now, it thinks it’s still a billion-dollar business. Meanwhile downloads, dominated by Apple’s iTunes, are going to grow ever so slowly. Which means that if digital music is ever really going to take off, it’s going to be up to subscription services like Spotify, which up until now haven’t gained any real traction.

Granted, ringtones aren't anywhere near as awesome a status update as is pretending to listen to Animal Collective on Spotify.