Danica Patrick has raced to the center of "Danica-mania" just three years after signing with the Rahal-Letterman racing team. When this All-American beauty of 23 competes, Indy Racing League attendance rises, TV ratings soar and Danica-inspired T-shirts and hats zoom off shelves. The rookie even landed Sports Illustrated's cover after the Indianapolis 500-without winning the race! (She finished fourth.)

Media exuberance isn't surprising: Who could resist the story of a 5-foot-2, 100-pound woman driving 230 miles per hour into the ranks of a tough, male-dominated sport? But how does a would-be superstar maintain perspective in the media swirl? Credit team owner Bobby Rahal, 52, a Motor Sports Hall of Famer, for keeping Ms. Patrick on track. "Ultimately, she's got to win races," he says. "If she doesn't, she'll just become another novelty."

Madison Avenue's interest has made her a top earner in motor-sports, with experts putting her net worth in endorsements north of $1 million and counting. Sponsors Argent Mortgage and Norwalk Furniture stepped up early; others have followed, among them American Honda Motor Co., Pioneer Electronics and Procter & Gamble Co.'s Secret antiperspirant. Endorsements include Hostess, Old World Industries (for Peak antifreeze and Mr. Clean), Argent, Bebe clothing and Tissot watches, plus others. While she has an agent and lawyer to broker deals, Mr. Rahal, who once had a stint at Young & Rubicam, also acts as Ms. Patrick's consigliere. "It's a fickle sport. ... if you don't deliver, you're gone."