BEIJING, China (CNN) -- Having completed his Olympics gold rush, U.S. swimmer Michael Phelps is now poised to make another haul -- this time of the endorsement variety.
Phelps already is collecting about $5 million a year in endorsement checks from companies like Visa -- payments that came after he won six gold medals during the 2004 Olympic Games in Athens, Greece.
His performance in Beijing, where he won a record eight gold medals, puts him in line to earn much more.
"He may be at $30, $40, $50 million a year in endorsements after all this is said and done," said David Harrow of the National Sports Lawyers Association.
Even before the Beijing Olympics, Phelps collected a million-dollar bonus from one his sponsors, Speedo. iReport.com: Ask Michael Phelps a question
"Michael came out of the Athens Games an American sports hero," said Michael Lynch, head of global sponsorship management at Visa. "He's coming out of these games a global sports icon."
Visa declined to say how much it pays Phelps, but whatever the amount, sports agents say they expect it to go up -- a lot. That could put him in the same stratosphere as soccer star David Beckham and golfer Tiger Woods, though Harrow doubted that Phelps is "at the $87-million endorsement number of Tiger."
Phelps said he will look back fondly on his time in Beijing. Watch how Michael Phelps can cash in »
"Outside the pool, inside the pool -- there are tons of memories," he said. "Every single one I will remember for the rest of my life."
Much of the United States was caught in the wake of Phelps' gold medal surge. And after the past week, it seems he may have made many new fans in China.
"He has done so much in these Olympics," one woman said. "He's a hero. He's great!"
"I really, really worship him," said one man. "He's really great."
For global companies looking for brand recognition in the world's fastest growing economy -- one made of 1.3 billion people -- Phelps may be pure gold.