NEW YORK (CNN/Money) - Lance Armstrong is the most successful and famous athlete that almost nobody has ever watched.

The defending four-time Tour de France champion -- who starts his try for a record-tying fifth straight championship Saturday -- has a roster of endorsement contracts that would make most athletes and their agents drool. Coca-Cola, Subaru, Nike and Bristol Meyers, along with other sponsors, pay him about $16.5 million a year, according to Outside Magazine.

Subaru is one of more than a dozen sponsors paying Lance Armstrong an estimated $16.5 million a year.

Armstrong is known by about 72 percent of U.S. sports fans, according to a survey of 1,800 fans ages 12 to 64 conducted by Marketing Evaluations Inc., about the same level of recognition as sport stars like basketball's Kobe Bryant, football's Steve Young and tennis' Williams sisters. And fans have overwhelmingly positive impressions of Armstrong, a cancer survivor who has come back to dominate his sport. His success both on and off his bike made him Sports Illustrated's Sportsman of the Year for 2002.

But the irony is that Armstrong's sport itself is one almost no one ever watches, at least on this side of the pond where he is far more popular than in France.

Far more Americans will see Armstrong pedal in commercials than in the races through the French Alps and countryside.

Most of the race coverage last year was on the Outdoor Life Network, a cable station available in less than 40 percent of U.S. homes. Race coverage had an average viewership of about 336,000 homes for the tour last year -- a number that essentially rounds down to zero in the world of television ratings.

Attention given to Armstrong, despite the lack of U.S. fans who actually watch him compete, is worth millions to his sponsors.

The three broadcasts of races on CBS last year were watched by between 1.2 and 1.5 percent of U.S. homes, putting them on par with viewership for such sporting events as arena football's championship game or the Winter Tour Rodeo Finale.

The race itself is not terribly television-friendly. A leader in any one stage of the race can be far back in the overall standings, while the overall leader can be caught well back in the pack on any one day of the race.

But Armstrong's success and compelling personal story have made him a media sensation that far transcends the sport and brings value to his sponsors. The U.S. Postal Service, which has sponsored his team since before he joined, estimates that free media coverage of its name and logo is worth about $19 million.

"The races themselves are a relatively small part of that. It's the cover of Sports illustrated, the front page of Washington Times," said Joyce Carrier, director of public affairs for USPS. That kind of publicity gives the postal service a good return on its investment, estimated at about $4 million annually.

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Other sponsors apparently feel the same way. Armstrong's agent Bill Stapleton said the lack of viewership for the races themselves is not a problem for the sponsors he's talked to. He says that he's in discussion to add additional sponsors and says Armstrong's list of endorsements will grow even if he doesn't win this year.

"It's about Lance and his story. It's not about how many people watch the bike race," said Stapleton. "His endorsement value gets a lift if he wins five in a row, but I don't think he's hurt if he doesn't win. It'd be really great if as many people watch the tour as watch the Super Bowl but that's not going to happen."

One of his main sponsors agrees that Armstrong's value has relatively little to do with his success or the popularity, or lack thereof, of his sport.

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"It's Lance overall, it's his story, his personality," said Subaru spokeswoman Lisa Fleming. "That doesn't change if he loses."

This year Subaru signed Armstrong to a three-year contract, along with an option for two more years. Fleming admits she and most other Subaru executives are like the great majority of Americans -- they'd never watched the Tour themselves in the past, even if they knew Armstrong and his story. But that'll be changing. The races will be carried on monitors in the hallways, in the cafeterias and in the auditorium of Subaru of America's headquarters.

Maybe Nike doesn't need to do that for Tiger Woods or Michael Jordan. But when you're the nation's least-watched sports superstar, every little bit helps.