FOR LIAM KILLEEN, THE GUY responsible for airing those TV ads for Mentos candies, life isn't always sweet. Just last month at a video store near his Erlanger, Ky, home, he was tongue-lashed by a clerk who spotted the logo on his jacket. "She went nuts," says Killeen, 33, a vice president of marketing for Van Melle, the Netherlands-based maker of Mentos. "She was saying, 'Mentos? I hate those commercials. They're so cornball! So stupid!' "

Not that he was offended. After all, it's the unintentional awfulness of Mentos's 11 TV spots that have put the candy company on a roll. Featuring an annoyingly infectious jingle ("Mentos fresh and full of life!") and plucky twentysomethings who solve simple predicaments (a blocked-in car, a waiter who ignores them) after popping the chewy mints, the ads, since their introduction in '91, have tripled Mentos's annual sales to $120 million. A cult phenom among teens and gen-Xers, the perversely appealing spots have also landed in the movie Clueless and been spoofed by David Letterman and the band Foo Fighters in its Big Me video. "When I first saw the ads," says Chad Jones, 25, a computer administrator who runs one of many Web sites devoted to Mentos, "I was like, 'Who are you kidding?' "

Now, with mocking Mentos becoming a national pastime, Killeen admits he's perplexed by claims that the ads are dorky. "Personally," he says, "I don't see it." But he and other execs at the company's U.S. headquarters in Erlanger aren't complaining. "Mentophilia has taken on a life of its own," he says. "We're enjoying it as much as anybody else."