Yahoo bought check-in service IntoNow for $20 million to $30 million in cash and stock in a bid to make video and TV companion viewing part of its offering for consumers and advertisers.

Just 12 weeks old, IntoNow is a startup spun out of video ad server Auditude and has 600,000 downloads of its iPhone app since January. The company uses audio fingerprinting technology to allow users to "tag" a TV show or commercial, similar to how Shazam identifies music. Last week Pepsi used IntoNow to deliver a coupon to the phone of anyone who tagged a new video ad for Pepsi Max.

IntoNowCEO Adam Cahan is staying with the company, along with his seven-member staff, to further build out the service. "We're focused on the idea of how we make this a much bigger platform and product," he said, adding that the company wants to "bring video, television and companion viewing directly into the product life at Yahoo."

The purchase price included $20 million in cash and stock up-front and incentives over time. The company is working on an Android version of the app and seeking to expand internationally.

Originally, the tech was developed to target video ads at specific TV shows on the web. Auditude encoded five years of TV from 130 different cable and broadcast networks and matched it with sophisticated ad-serving technology. That business stayed with Auditude, which hired former United Online executive Jeremy Helfand as CEO. With that fingerprinting technology, IntoNow can tell not only what a person is watching, but whether they're watching video live on TV or played back later on a DVR or online.

Mr. Cahan said last week before the Pepsi promotion that it had had 3 million "tags" since January, and can recognize a given video clip in four to 12 seconds.