Sisters to appear in new 'Whoa' TV campaign.

With the introduction of its new gum, IceBreakers Ice Cubes, the Hershey Company has re-upped its partnership with Hilary and Haylie Duff. The Duff sisters appear in the multi-million dollar "Whoa" TV ad campaign. Created by the North Castle agency in Stamford, Ct., the IceBreakers Ice Cubes "Whoa" spot also features sports personality Keith Jackson, actor Joey Lawrence and others delivering their best "whoa's."

As part of the deal, the Duffs will make a NASCAR appearance Feb. 26 at the California Speedway in Fontana. The sisters will wave the green flag to start the race. Kevin Harvick will man the No. 29 IceBreakers Ice Cubes Nextel Cup car.

In June, the Duffs will help promote a new mint in the IceBreaker brand line, according to Arnaud Gadaix, Hershey brand manager of gum products. And if the Duffs go on tour, IceBreakers Ice Cubes will be the title sponsor.

Gadaix says consumer research has shown that the Duffs/IceBreakers partnership resonates well with teens and young adults, which is a bull's-eye for the brand. "They're the early adapters," Gadaix says of that audience. "We know that that target audience will try the product first." And if they like it, Gadaix says they will communicate this to others, via blogs and personal websites.

The Duffs and Hershey first partnered last year when the sisters became the new faces of IceBreakers Liquid Ice mints. In this role, Hilary and Haylie followed in the footsteps of Jessica and Ashlee Simpson, who helped launch the then-new mint with the "Is it liquid or is it ice" campaign in 2004.

Hilary Duff's 2005 trek was sponsored by IceBreakers Liquid Ice; it was the 25th top grossing tour of the year, according to Billboard Boxscore, bringing in $18.1 million and attracting 439,735 fans across 48 shows.