The world's most famous athletes don't rely on just one revenue stream - oh no, £100,000-a-week wages from Barcelona or $1m prize money pots from the PGA Tour are just your basic take-home pay for the globe's finest sports men and women.
Image rights is where they real money is at. Spanish newspaper El Diario has published the latest table of the world's highest earning athletes from advertising - and Swiss tennis star Roger Federer sits on top.
The research, conducted by Euromericas Sport Marketing agency, claims the grand slam superstar has earned $68m through endorsements and advertising in 2013. Not bad.
But how does that compare the top athletes in other sports? Here, we count down nine of the highest earners as revealed in the El Diario report.
Think you can guess who makes the list? Leave a comment with your picks below and then click through the slideshow to see how you got on...