Roger Federer may become the first tennis player to reach billionaire status.
Most of Federer's wealth did not come directly from the game.
The majority of his earnings come from lucrative sponsorship deals.
He's partnered with Gillette... Nike... Uniqlo... Credit Suisse... Mercedes-Benz... Moët & Chandon champagne.... The tennis star won his first Grand Slam at Wimbledon in 2003.