By Jeanine Poggi
Advertising Age

Is an online viewer just as valuable to advertisers as a TV viewer? Up until now, the answer was no. Nielsen is looking to change that with the introduction today of its Cross-Platform Campaign Ratings, which will measure the number of people who watched a campaign only on TV, the number who viewed it digitally and the overlap between the two.

"This is the first time we can show the number of people who saw a campaign no matter where it lived," said Steve Hasker, Nielsen’s president of global media products and advertiser solutions.

Since traditional TV and the web typically use different metrics, it has been hard to calculate a campaign’s total reach and frequency across platforms. This effort builds upon Nielsen’s Online Campaign Ratings, which was rolled out last year to provide demographic ratings of online-ad campaigns with metrics comparable to those used for TV advertising.

So far, OCR has been used by pure online players like AOL to offer guarantees to advertisers. But beginning this fall, the CW will also adopt the measurement as a major part of its digital-advertising strategy. The CW move shows how cross-platform metrics could give TV networks more flexibility in their ad packages and a better sense of a program’s digital traction.

The network, jointly owned by CBS and Time Warner, will tag every online video ad and use OCR to offer advertisers demographic guarantees for all online campaigns of the 2012-2013 season. If these guarantees fall short, it will provide make-goods.

Last week the CW renewed summer dance docu-drama "Breaking Pointe" despite lackluster TV ratings, citing its success online. The show, which focuses on the dancers of the Salt Lake City Ballet, on average garnered only about 966,000 total viewers each week, bottoming out with about 620,000 viewers. This is low even for the CW, whose series like "Hart of Dixie" and "Nikita" had on average about 1.8 million total viewers last season. But the CW claims "Breaking Pointe" was a digital success, though the network would not reveal its online ratings.

Cross-platform ratings have been tested by ESPN, Facebook, Group M, Unilever and Hulu, but Mr. Hasker said it’s too early to tell if more ad dollars will flow from TV to online as a result.

"This is helping to equalize buying across online and TV," said Kate Sirkin, exec VP and global research director for Starcom MediaVest Group, whose clients use Nielsen’s online campaign ratings, adding efficiency and ensuring "we are not duplicating in areas."

"While having a similar metric isn’t bad, Nielsen is oversimplifying it and trying to say everything is equal," said Michael Hayes, president of digital communications, Initiative Worldwide. How people watch TV is different from than how they engage with their digital devices, he argued. "TV watching hasn’t changed for decades; it’s a lean-back mentality," he said. But consumers can use tablets in different ways. They can do research while on the car lot or while watching TV to learn more about a car ad.

"Digital buyers plan differently and buy media based on the context," Mr. Hayes said. "There are times when we are looking for the inverse of [gross rating points] — less impressions and less frequency to hit the right consumer."