It seems unusual to most people that an athlete could earn more from endorsement, advertising and sponsorship deals than they actually get paid for doing the very thing that has made them so famous, but the reality is that it far from a rare occurrence. The greatest sporting figures are recognizable faces across the globe, as well known as the biggest movie or pop stars, and therefore it is not surprising that they are targeted by major companies and brands.

Furthermore, some sports do not pay their athletes as lucratively as you may think. Of course, the likes of soccer, football, basketball and boxing all pay their top athletes huge fees, but many of the athletes on show at the Olympics who compete in less watched sports which are not awash with cash do not always earn a great deal. As such, these athletes often rely on endorsement deals for a hefty chunk of their income.

There are probably hundreds of athletes who earn more through endorsement deals than through playing sport, but these are 15 interesting cases, with some athletes earning as much as 99% of their income through endorsements. Here are 15 athletes who make/made more money off endorsements than playing their sport:

15 15. Neymar

Brazil star Neymar is the only top soccer player in the world to earn more from endorsements than from his club right now. After his controversial transfer to Barcelona which may have made him the most expensive player in soccer history, Neymar's contract with the Catalan club sees him earn $14 million a year, meanwhile his endorsements total in excess of $17 million. Neither Cristiano Ronaldo nor Lionel Messi earn more through endorsements than playing, this is largely down to them earning more at their clubs and also the fact that Neymar is a huge national hero in his native Brazil.

14 14. Rafael Nadal

Current world number 10 Rafa Nadal has struggled with injuries and form for almost two years now, but when he was at his best, he was the best tennis player in the world. He is widely regarded as the greatest clay court player ever and one of the greatest all-round tennis players of all time. Nadal's drop in form has seen his playing salary/winnings drop down to $4.5 million, but his endorsements still make him a sizable $14 million a year, making him still the third highest earning tennis player in the world today. Nadal's leading endorsement deals come from Nike and Armani.

13 13. Ernie Els

Former world number one, Ernie Els, now finds himself way down the rankings in position 107, but that hasn't stopped his huge endorsement earnings. With his winnings down to just over $3 million, Els still earns $16 million through his varies endorsement deals. Els has a total of 67 career victories, which include four major championships. At his peak, Els topped the European Order of Merit for 2003 and 2004. Els also became the first athlete to be individually endorsed by Boeing.

12 12. Maria Sharapova

Maria Sharapova is one of the finest female tennis players of her generation, with the Williams sisters being the only active female players who are more successful than her. Sharapova made a huge impression as a youngster, becoming world number one at the age of just 18. She has struggled for injuries for much of her career but has managed to win at least one singles title every year between 2003 and 2015. Sharapova is the highest earning female athlete in the world. She earns $6.7 million through her tennis playing and $23 million in endorsements. Sharapova has a number of major brands she endorses, including Head, Cole Haan, Nike, Porsche and Samsung.

11 11. Sachin Tendulkar

Cricket is big business across much of the world, and nowhere more so than India, where Sachin Tendulkar is from. Most consider Tendulkar to be the greatest batsman of all time and many the greatest cricketer all-round. He retired from cricket fully in 2013, after a quite remarkable career; he is the only man to complete more than 30,000 runs in international cricket. In his playing days, Tendulkar made around $4 million a year from the sport, whilst even today his endorsements are worth an incredible $18 million. Tendulkar's major endorsement deals were with Adidas, Coca-Cola and Toshiba.

10 10. Li Na

Tennis star Li Na was sadly forced into early retirement in 2014, when she was playing some of her best ever tennis. The Chinese sportswoman reached her record highest position of world number 2 shortly before her career-ending knee injury at the age of 32. Prior to her retirement, she won two Grand Slams, making her the first tennis player from Asia to do so. She earned a considerable fortune of $5.6 million through tennis but still made far more through endorsements which saw her pick up over $15 million through deals with Mercedes-Benz, Nike, Rolex and Samsung.

9 9. Mahendra Singh Dhoni

Mahendra Singh Dhoni is the highest paid cricketer in the world right now, and one of the best paid athletes. Widely regarded as India's greatest ever captain, Doni has an astonishing list of records over his career, including being the only man to be named ODI Player of the Year twice, and he is still going string at 33. Dhoni is one of the most recognizable faces in India, making him hot property, and Reebok, United Breweries and Pepsi have all leapt at the opportunity to have Dhoni endorse them. He earns $4 million a year through cricket and a whopping $27 million through endorsements, which account for 89% of his total earnings.

8 8. Phil Mickelson

Phil Mickelson has won five major championships, with the U.S. Open the only major which has eluded him, and he has finished as runner-up a record six times for that major. Mickelson has spent over 700 weeks in the world top 10, but has never been world number one, spending a fair amount of time as world number two. 'Lefty' as he is commonly known, has made just shy of $4 million in career winnings but an incredible $48 million in endorsements with Enbrel, KPMG, Rolex and Callaway, which account for over 90% of his total earnings.

7 7. David Beckham

The world's most famous footballer of his time, David Beckham is a global superstar. Soccer is the most popular sport on Earth, so it is little surprise that it's most recognizable face receives huge endorsement deals. In a glittering career, Becks played for Manchester United, Real Madrid, L.A. Galaxy, A.C. Milan and PSG. He has also played 115 times for England, a record for an outfield player. Beckham retired in 2013, and despite nowhere near one of the best players in the world by that stage, he still earned more than Messi or Ronaldo, totaling earnings of almost $50 million.

His club wages earned him $4.2 million, whilst he made $42 million in endorsement deals. In 2003, he signed a deal worth $160 million with Adidas alone, whilst Armani more recently agreed a $40 million deal with the superstar. Other endorsement deals have been made with Pepsi, Breitling, H&M, Burger King, Samsung, Diet Coke, and many, many more. Beckham's total worth is in excess of $350 million, with 89% generated through endorsements.

6 6. Michael Jordan

Michael Jordan is estimated to be the wealthiest sportsman of all time and the first ever billionaire sportsperson. He is widely considered to be the greatest basketball player in history, and his skills in the court have been marketed expertly. Despite retiring 12 years ago, Jordan is estimated to be currently earning $100 million a year. He has endorsed major brands and companies such as Coca-Cola, Chevrolet, Gatorade, McDonald's, MCI and many more, but none come close to the deal he signed with Nike to sell the 'Air Jordan' sneakers. Released in 1984, J's, as they are commonly known, still sell well today.

5 5. Roger Federer

Tennis legend Roger Federer is the most successful and many consider the greatest tennis player of all time. He has won 17 Grand Slams, more than any other man in the history of the sport, and is still world number 2; his longevity and success is unprecedented. He has made more money in winnings than any other tennis player in history, earning $6.5 million through his success on the court annually; but this is still dwarfed by the $65 million a year raked in through endorsement deals. Federer's biggest deals have been with Nike, Mercedes-Benz, Moet & Chandon and Gillette, he is estimated to be worth around $350 million.

4 4. George Foreman

Whilst most on this list have a variety of endorsement deals which see them earning a fair wad, George Foreman needed only one. The George Foreman Grill has sold over 100 million units worldwide, earning Foreman an estimated $200 million, far more than he ever made in his boxing days and taking his total worth up to $250 million. A former heavyweight champion, Foreman appeared as an unbeatable machine when he arrived on the boxing scene, until Ali knocked him out in the Rumble in the Jungle. Foreman was destroyed by the defeat and retired soon after, but returned 10 years later to regain the belt aged 45.

3 3. Tiger Woods

Tiger Woods has been one of the best-paid athletes in the world for around two decades, and he is now valued at $640 million. Regarded by many as the greatest golfer that the world has ever seen, Woods won his first major in 1997, having turned professional at the age of 20. He has won a total of 14 major golf tournaments over his career, and been ranked world number one for longer than any other golfer in history. After a slump in form, Woods' annually earnings are down to $600,000, yet he is still earning $50 million in endorsement deals, meaning around 98% of his earnings are not through golf.

2 2. Anna Kournikova

Retired tennis player Anna Kournikova was, with the greatest deal of respect, not the greatest tennis player you will ever see. Unlike Tiger Woods, Roger Federer and Michael Jordan, she was never at the top of her sport, yet she was consistently the highest earner in women's tennis. Kournikova never won a Grand Slam title and her highest ranking was in eighth place in the world. Over her entire career, she made $3.5 million through her tennis exploits, yet she is valued at over $50 million, an indication of how Kournikova has profited through various endorsement deals with the likes of Adidas and Berlei.

1 1. Usain Bolt 

Track & field athletes rarely make a great deal through their sports, and often have to rely upon endorsement deals. No one epitomizes that better than the fastest man on Earth, Usain Bolt. The 100 and 200 meter world champion makes at most $200,000 a year, and sometimes as little as $15,000 a year through his sprinting, but almost $25 million a year through his various lucrative endorsement deals, most notably with Puma, Gatorade and Virgin Media. Bolt's record of running the 100 meters in 9.752 seconds, where he hit almost 30 mph makes him, as far as we know, the fastest human to ever live.