Marketers' increasing clamor for measurement of advertising effectiveness has inspired Omnicom Group's entertainment-marketing unit Davie-Brown Talent to launch a new service that quantifies the public appeal - and therefore the marketing value - of celebrities, actors, news anchors and sports personalities used for product endorsement.

Among the stellar pitchmen (and women) most highly rated by D-BT are Tom Hanks, Tiger Woods and Oprah Winfrey. With masterly understatement, D-BT president Jeff Chown, opines: "Some of these celebrities cost quite a bit of money."

An advertiser, he adds, "needs to know if they are getting their return on that investment."

Omnicom's new venture muscles-in on a market dominated by a single practitioner, Long Island-based Marketing Evaluations, which conducts regular surveys to samples selected from a 100,000-strong national database. The surveys, known as Q Scores, probe celebrities' likeability and familiarity among the general public.

The Omnicom proposition is on a far larger scale. The Davie-Brown Index, as it is known, will be based on regular surveys of consumers drawn from a 1.5 million-strong research panel, to which a list of over 1,500 celebrities will be presented four times a year.

Data sourced from Wall Street Journal Online; additional content by WARC staff