To get a sense of how much money Michael Phelps is likely to make in the next 10 years, imagine each of those eight medals around his neck as 1,000 pounds of solid gold.
That's roughly equivalent to the $100 million payday anticipated to come to the star swimmer during his lifetime, according to his agent and sports marketing experts.
With his stunning achievement in breaking Marc Spitz's 36-year-old record for most gold medals in a single Olympics and his ubiquity on TV, radio and the Internet, Phelps is expected to bank much more than previous Olympic champs such as "America's Sweetheart" Mary Lou Retton, decathlete Bruce Jenner and track star Carl Lewis.
But he's not going to hit the stratosphere of sports marketing occupied by Tiger Woods, whose career earnings are expected to hit the $1 billion mark in 2010, or Michael Jordan, who reportedly has made more than $500 million in his career.
Though most viewers won't see him in action again until the 2012 Olympics in London, his phenomenal success should translate into major dollars in the intervening years, says Doug Shabelman, president of Burns Entertainment.
"He will be a force to reckon with on the endorsement front because he transcends his sport," he told ABCNews.com. "You don't need to watch swimming to know who Michael Phelps is."
Though he's finished swimming laps in competition, Phelps will spend the rest of his time in Beijing making appearances for sponsors like Omega watches, Hilton Hotels and Visa. And Peter Carlisle, his agent, says that he's been busy fielding offers -- from book and movie deals to dog-food makers keen to take advantage of Phelps' love for his British bulldog, Herman.
And his current sponsors have been reaping the benefits of his success, which should translate into more lucrative deals in the future. Speedo says that it sold out of tens of thousands of $24.99 Phelps jerseys, even though swimmers don't even wear shirts.
Other marketers are already jumping to take advantage of Phelps' popularity, with Match.com announcing a recent survey of its members in which 81 percent picked Phelps to be on their "dream team." Even Phelps' mother has become a hot commodity, with Johnson's issuing a press release Saturday naming Debbie Phelps its "Baby Mom of the Olympic Games."
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Shabelman sees Phelps easily exceeding the success of Retton, because there are so many more branding opportunities available to him in the globalized world of media and advertising, from guest appearances on "American Idol" to ads on Web-based platforms.
Nevertheless, Retton's long-term success bodes well for Phelps.
It's been almost 25 years since she bounded her way into the hearts and minds of America at the 1984 Olympics but Retton is earning more now through speeches and endorsement deals than at any time in her career, says Michael Suttle, her manager.
She makes about 10 to 14 corporate speeches a year, each one netting her $25,000, and has endorsement deals with Tyson Foods, Biomed orthopedic manufacturer and GNC nutrition stores, Suttle says.
"She was able to connect early on with Madison Avenue and everyone else in marketing and PR out there and her income is still very significant," he said.
But Phelps is limited in his ability to reach the highest levels in the business of sports because swimming is not a popular sport and he only competes on the big stage every four years, compared to professional athletes like Woods or NBA star Lebron James.
"He could become old news because the public won't see him every day -- though Bruce Jenner managed to hang on for a long time," said Andrea Kirby, who was the U.S. Olympic Committee's first media coach in 1996.
"Reggie Jackson once told me about all the attention that Jenner was getting, 'The man's only got one home run. It's only one game. How far can you take that?'" said Kirby.
"As a New York Yankee, Jackson was in the front pages almost every day for most of the year. But as an Olympic star, you're only in the bright lights for a few weeks," Kirby said. "You have to make the stardom last and it's not going to have the same staying power."
The best parallel for Phelps is the career of Lance Armstrong, Shabelman says.
"He was only racing the Tour de France, which only takes place once a year, but Lance was able to find success with endorsement deals -- Nike put him on a pedestal -- and initiatives like his Live Strong Foundation," he said.
It hasn't hurt Armstrong that he regularly makes the gossip columns by dating stars like Kate Hudson and Sheryl Crow, increasing his visibility among the celebrity-hungry public coveted by advertisers.
Phelps may already be on his way in that regard -- he's recently been linked to Olympic record-holding swimmer Amanda Beard, who recently posed nude for an anti-fur ad campaign and in the pages of Playboy, and to British model Lily Donaldson.
"It'll be a good future for Mike," Suttle deadpanned.