To date, Google TV Ads has deals to sell local advertising avails on EchoStar's DISH Network satellite TV service, and national TV ads on a handful of mostly low-rated or emerging cable TV networks.

The deal is the latest effort by Google to leverage enhanced data to make the Google TV Ads platform more attractive to advertisers, and consequently, more appealing to bigger TV networks to begin using to sell their advertising time.

Google TV Ads primary source of data comes from the digital set-top devices of DISH Network subscribers, and a few small digital cable TV systems that have partnered with Google. Google subsequently enhanced those TV audience data streams by licensing demographic TV audience information from Nielsen Co., and more recently by licensing geo-demographic analytics data from Nielsen's PRIZM system.

The new deal with TiVo gains access to second-by-second DVR viewing data, which will give Google TV Ads advertisers insights about household-level advertising impressions generated by their buys, but it does not include any of the enhanced analytics generated by TiVo's StopWatch service, which is not covered by this deal.

Google hasn't disclosed how much TV advertising is actually being processed through its platform, but the system is believed to be popular mainly with direct response and "long tail" advertisers and agencies, and among bigger agencies using it primarily to test and gain insights about TV audience exposure via the system, which competes with Microsoft's NAVIC, and Spot Runner's Malibu platforms. The cable TV industry's Canoe Ventures also is seen as a potential competitor or collaborator with Google TV Ads, but its long-term market play still remains unclear in the minds of many TV buyers and sellers.

Meanwhile, the amalgamation of TV audience data streams and analytics tools being assembled by Google TV Ads has been both intellectually attractive to Madison Avenue, as well as confusing, as was evident during a series of presentations made by various data suppliers and end-users during a TV audience measurement summit held by Google earlier this month.

During one of those presentations, Nielsen Senior Vice President-Insights, Analysis and Policy Pat McDonough, noted there still are a number of problems with the kind of set-top data being used by Google TV Ads, including the fact that it's difficult to know when people are actually sitting in front of their TV sets when the set-top devices are on and tuned to a channel. According to Nielsen's estimates, 10% of digital set-top devices "never get turned off," and 30% are on for 24-hours in any given day. While methods have been developed for editing the digital set-top data to factor out the non-viewing portion of their tuning, the real value is in reporting the "long tail" of the TV universe - the part not measured by Nielsen's traditional TV methods.

During another presentation by full-service New York-based agency Karlen Williams Graybill Advertising, which showcased the results of an actual TV buy made earlier this year for the Act and Gold Bond Ultimate brands across eight cable TV networks, comparing both Google TV Ads and Nielsen's conventional TV ratings samples, the agency concluded that there were no "statistically significant" differences, and that, "There is no perfect rating methodology."

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