"That has proven to be without question our most effective ad," Mr. Higgins said.

Now, as clients increasingly hold agencies accountable for effective ads, the researchers are being eagerly sought out.

Bingaman still serves in the Senate, a beneficiary of one of the most polite and effective negative ads ever run.

"I remember coming out of there thinking it was the most effective paid ad a candidate could ever have."

The bill's length gave credibility to the effective ads the health insurance companies were already running against the plan.

Use his most effective ad against him.

In his statement, Mr. Saemann said the Catapult commercial had been one of the company's most effective ads.

That research later provided the grist for some of the most effective ads against Mr. McCall.

This system encourages advertisers to write effective ads and to advertise only on searches which are relevant to their advertisement.

"This is an effective party-building ad and we are continuing to use it," he said.