TiVo on Thursday started selling demographic information and other subscriber data to advertisers, as the company searches for other revenue streams to counteract increasing pressure from cable, satellite, and telephone companies.

TiVo has been selling to advertisers second-by-second ratings of programs and commercials based on the viewing habits of subscribers for about a year. But this is the first time the service -- dubbed Power Watch -- expands on the available information by providing data that could help advertisers understand why people watch or skip TV ads.

The new service provides demographic data on subscribers, such as age, income, marital status, and ethnicity; it also lets advertisers pose questions to some TiVo subscribers. The latter feature could shed light on viewers' habits and feelings toward particular advertisers and marketers.

Power Watch gathers its information from 20,000 TiVo subscribers who have opted in to the program. Starcom MediaVest Group, which manages advertising for companies, is the first customer of the new service.

"With 20,000 households, the Power Watch Consumer Panel will provide a new level of detail on DVR viewing behavior among any given brand's target segments that will significantly enhance the approach advertisers take in creating and buying advertising on television," Todd Juenger, VP and general manager of audience research and measurement for TiVo, said in a statement.

TiVo is under growing pressure from cable, satellite, and telephone companies that sell DVRs (digital video recorders) to subscribers. The company in August reported a widening loss in the quarter ended July 31 due to an inventory write-down and purchase commitment charge. TiVo-owned subscription gross additions fell to 41,000, compared with 74,000 a year ago. Nevertheless, the company expects to break even based on earnings before interest, depreciation, and amortization for fiscal 2008.

Besides the ad-information market, TiVo has also been trying to increase the role its DVR plays in the home. Rather than have it only be a cable box, TiVo has introduced models that it's positioning as Internet hubs for the home.

Last month, TiVo announced a deal with RealNetworks to offer the latter company's Rhapsody online music service through TiVo's broadband-connected DVR. TiVo's growing list of Web partners includes Amazon and Yahoo.