CBS spent $280 million in cash to acquire Last.fm, which claims 15 million-plus active users in more than 200 countries. The potential isn’t limited to radio; this is more about community and technology, in some respects, than music. From the release: “The Last.fm management team will work with all relevant CBS divisions to apply their community-building and technology expertise to extend CBS businesses online and within the mobile space.” Last.FM already is working on a video channel.

Last.fm raised its first round of funding—an undisclosed amount—last May from Index Ventures, the same firm that backed Skype and has invested in Joost. (CBS also invested in Joost and the two companies are both backing Spot Runner.) Angel investors included Joi Ito, Reid Hoffman, and Stefan Glaenzer.

Co-founder Richard Jones wrote in the company blog that the team was considering raising additional funding when CBS approached. Jones: “As you can imagine, we have been approached numerous times in the past few years from all the usual suspects regarding acquisitions and so on; CBS are one of the few companies who needed no explanation of what we are doing, and we were impressed at how progressive their plans are.”

CBS has made a lot of announcements lately about plans—Wallstrip, Joost investment, the audience network, spcial media. Next step: seeing some results.