Slacker is bulldozing the thin line dividing itself from subscription-based music services today, with the launch of Premium Radio. The new pricing tier joins the existing gratis Basic Radio and ad-free Radio Plus plans, adding an all-you-can-eat music model akin to services like Rhapsody and Rdio. Subscribers who shell out $9.99 a month receive all of the features of the $3.99 Radio Plus users, plus unlimited access to eight million songs, letting them listen to what they want, when the want, and generally play god with the site's existing radio services. Premium Radio also gives you on- and offline access to music on a number of mobile devices, including the iPad, iPhone, iPod touch, Android, and BlackBerry handsets -- not to mention unlimited bragging rights to all of your broke friends who are still rocking the Basic Radio plan. Don't feel too bad for 'em, though -- at least they didn't get suckered into slotRadio.