Marketing professor Jeff Stoltman of the School of Business Administration commented about Cadillac's new ad campaign - "Life. Liberty . And the Pursuit" - which debuted Sept. 29. The campaign uses different types of music in 15 TV spots. It follows one that used Led Zeppelin's music to help breath new life into the brand's stodgy nameplate in the face of stiffer foreign competition for luxury car customers. "We want to tell the story of what American luxury means," said a spokesman for the ad agency that created the campaign. Stoltman noted that "campaigns go through a wear-out phase. After a while, people just tune it out."