Google, which dominates the Internet ad space, and the Nielsen Company, the definitive voice in measuring TV audiences, have joined forces to give advertisers a more realistic and accurate measure of how many people are watching their TV commercials and who these people are.

It’s a long way off at the moment, but the teaming of Google and Nielsen and the information they produce could one day alter television advertising, disrupting the way ads are created, how they are sold, how they’re targeted, and ultimately what we as viewers see at home.

“We can make advertising more relevant to the viewer at home,” said Mike Steib, the director of the Google TV Ads program. (BusinessWeek.)

“We want to bring all the advantages that we see in online advertising — like more accountability, a better sense of audience, better tools to optimize a campaign — and bring them to television to make TV advertising more effective,” Steib said. (New York Times.)

“We see a future in which, when you sit down in front of your television set, you will see ads that are more relevant for you,” he said.

For now, the Google TV Ad program is selling advertising on only EchoStar Communication’s DISH Network, which has about 13 million subscribers, and it will need to reach other cable and satellite TV networks to be truly revolutionary.

But the possibility of what Google and Nielsen can deliver together is impressive and might be enough to bring others along, even though Time Warner Cable — a big-time content owner — might be reluctant to work with Google due to its YouTube video sharing site. Comcast recently signed a search deal with Yahoo!, not Google.

With Google TV Ads, Google now analyzes data from set-top boxes second-by-second to determine exactly which ads were watched or skipped. The advertiser receives a report the following day listing total viewers who watched an ad. In these reports Google can pinpoint the moment viewers change the channel.

With Nielsen in the mix, Google can now take Google TV Ad information and overlay Nielsen’s sampling-based ratings to add a rich, detailed demographic layer that hasn’t existed before. Nielsen’s data fills in many blanks and can provide advertisers and agencies with comprehensive information to help them create better ads for viewers and maximize their advertising investment.

The deal with Nielsen indicates just how serious Google is when it comes to TV advertising and moving itself beyond the Internet to all sorts of media. Vincent Dureau, Google’s head of TV technology, predicted at an Internet TV conference in July that Google TV Metrics were on their way.

Now they’re here.

Dave Morgan, founder and chairman of Tacoda, an online ad agency recently acquired by AOL, predicted to the NYT that Google will find itself with more power and influence in all forms of advertising over time.

“They are shaking up Madison Avenue to a degree that’s extraordinary,” he said.

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