Once upon a time, Shazam, the mobile app that identifies songs by listening to audio clips, was just a fun gadget to show your friends (“wow, it really works!”). But the nine-year-old service has nearly doubled its userbase to 35 million since September, claims a tenth of users actually buy the tracks they hear and has ambitious plans for the year ahead.

SEE ALSO: Shazam Launches Android App, Music Downloads Via Amazon MP3

London-based Shazam, which has 60 staff and a new San Francisco office, may be hard-wired some in to Motorolas, to AT&T (NYSE: T) and be available via a dial-in number, but its growth is being fuelled by app stores, which, as Apple’s latest campaign demonstrates, are now hitting the mainstream. Shazam was iPhone’s number-seven app on launch day, Android’s third and, most recently, BlackBerry’s top download. Following the uptick, it will launch on more app stores in the coming weeks, CEO Andrew Fisher revealed to mocoNews.net…

“Until now, it’s been about convincing the service providers that Shazam has value. The app store has changed all of that - to get mass distribution, you can now convince the customer. We’ve seen fairly exponential growth kick in. Since last September, we’ve had 15 million new users - prior to that, we had built 20 million users over the last eight years. Given what’s happened, the focus right now is to get to 50 million by end of the current calendar year and 100 million by end of 2010. We feel that’s important, because then it starts to become comparable to some of the large internet properties.” Read the full interview at paidContent:UK...