CBS Corp. (NYSE:CBS) took another step into the internet world yesterday with its $280 million purchase of online social networking/music site last.fm. This follows last week's acquisition of the internet stock market show WallStrip.

Last.fm acts as both a music guide and internet radio/music distribution site. Members allow the site to track their PC/iPod listening habits, and the site customizes streamed content of new music matching their tastes. Last.fm also allows artists and labels to upload new music (with accompanying permissions), so they can (hopefully) build a following.

The UK-based site began five years ago, and now claims 15 million members.
CBS still owns the largest radio network in the U.S., and I'm interested to see if and how they might integrate last.fm into this business. The two seem to be, to some extent, competing technologies, one in decline (radio), one ascendant (internet). The sale came as a surprise to some pundits who had speculated Viacom (NYSE:VIA), until recently part of the CBS empire, was prepared to offer as much as $450 million for last.fm.

Last.fm could provide CBS with a valuable platform for distributing content and a channel to retain advertising flowing to the internet. However, at present, no one site clearly dominates the music networking world. While CBS now has a seat at the table, the fight for ears and eyeballs will continue to grow more interesting.