A Real Whopper? NASCAR's Stewart to take live polygraph test in ad

Burger King's no stranger to online advertising gimmicks. Remember the "Whopper Sacrifice" from earlier this year, when Burger King asked Facebook members to sacrifice friends to win a free burger?

The company's got a new online ad campaign that's playing on the questionable truthfulness of celebrity endorsements. How many times have you questioned whether the stars really enjoy the products they're hawking?

To help assuage doubts, Tony Stewart, the NASCAR driver and more recent Burger King pitchman, will take a polygraph test in a live online spot scheduled to air on Oct. 20. As the ad copy says, "Tony Stewart says he loves the Whopper, and he's taking a polygraph to prove it."