The partnership with ComScore aims to let Google and advertisers on its sites track specific data on user demographics to help advertisers reach their intended audience.
"It could lead to people pulling or changing ad campaigns" much more quickly, as companies would get Google users' feedback about ads in minutes instead of days, said Senior Editor Scott Stein.
Advertisers have received little feedback on the effectiveness of more traditional advertising, but the immediacy of online ad metrics have made companies "hyper-aware" of responses, which could lead to some being disappointed, Stein said.
(Read more: Google strikes big ad measurement deal with comScore)
"There could be a response where people might say, you know, I'm not getting very much engagement, why am I spending this money?" he said.
—By CNBC's Althea Chang