Google is putting its chocolate into Nielsen Media Research’s peanut butter. The two companies have signed a pact to cooperate on measuring the effectiveness of TV advertising. Currently, companies can buy Google TV Ads only on the Dish satellite network.

Google is bringing second-by-second analytics and feedback to the TV advertising world, but all it can do right now is measure what’s happening inside the set-top box. The deal with Nielsen will allow Google to add a crucial layer of demographic data. The combination of Google’s second-by-second reporting of which ads are being watched with Nielsen’s panel-based demographics should prove delicious to advertisers. Now all Google has to do is gain a foothold in other cable and satellite TV networks besides Dish.

We’ll let you know when that happens.