Some five years after buying media identifying service Gracenote for $260 million, Sony is selling it off to Chicago-based media company Tribune Co. for nearly half that. The two companies today announced a $170 million deal that gives the Tribune Company's Media Services group Gracenote's technology and database of 180 million music tracks and videos. That technology is used in products like iTunes to identify music tracks from imported CDs, as well as serve up track information in online services like Spotify and Pandora.

Gracenote gets more than half a billion "look-ups" a day

Gracenote says its database gets 550 million "look-ups" for media identification every day. That task will be handled by the Tribune Media Services group if the deal is approved early next year. That service has become increasingly popular with apps that let people attempt to identify music and TV shows from their smartphones in apps like MusixMatch. It's also what powers part of Microsoft's Xbox Music service when users match tracks from their library.

Beyond music — which is what Gracenote began with in 1998 — the company has been working on technology that identifies what users are watching on TV to better target advertisements. That's of particular interest to advertisers with the rise of the DVR and second-screen watchers who tune out when ads come on.