Mog's working hard to compete with Spotify and Rdio, so it's bundling its app anywhere it can — the latest is AT&T's new Samsung Galaxy S II Skyrocket and HTC Vivid phones. Mog recently integrated with Facebook and added 160,000 users in October alone but like similar services it's going to have to add paying users to stay alive. To that end, Mog's hooked up with AT&T's billing system so that customers can pay for the service with their regular phone bill. Exclusive preloads like this are an interesting tactic to try and get in front of potential subscribers first; Mog's bundled on devices like the Nook Color but still has to compete with other preloaded music apps. 

Skyrocket and Vivid owners will get a seven-day free trial with the preloaded service, after which they'll have to pay for it, but no separate sign-up process will be required — it's a lot easier to just pile on to a bill you're already paying, right? We'll see if new Skyrocket and Vivid owners will pony up — after all, if you're in the right market, the $100 discount on the new phones will leave you with some extra change for a music subscription.