The undefeated Floyd Mayweather recently announced his next fight will be against Marcos Maidana on May 3 at the MGM in Las Vegas. Regardless of the outcome, Mayweather is slated to make over $90 million in 2014. Despite Mayweather's success in the ring and at the negotiation table, endorsement deals remain an untapped revenue source and have the potential to take "Money" to a whole new level.

Past revenue

The first fight after Floyd Mayweather returned from retirement was a unanimous decision victory against Juan Manuel Márquez. Over his next five fights, Mayweather defeated Sugar Shane Mosley, knocked out Victor Ortiz, beat Miguel Cotto, then Robert Guerrero, and last September triumphed over Saul Canelo Alvarez. The purses for these fights totaled over $120 million. Throw in a $20 million WWE appearance fee, and Mayweather enters the $140 million+ range in just the past five years.

Here's the caveat: these were just his guarantees. This is money the promoter cuts to the fighter in advance of the fight. But because Mayweather owns his own promotion company, Mayweather Promotions, he also taps into the income from pay-per-view sales. This combined with certain buy benchmarks, a key partnership with Oscar De la Hoya's Golden Boy Promotions, and the exclusive Showtime deal (elaborated below), routinely places Mayweather atop Forbes' and Sports Illustrated's highest paid athlete lists. The Canelo fight alone generated record-breaking $150 million in PPV revenue from 2.2 million buys. Just for that fight, Mayweather earned a guaranteed purse of $41.5 million. After the PPV haul, final earnings for Mayweather were reported to be around $80 million, which would make it the richest take of all time.

Boxing's biggest broadcast deal ever

In February 2013, Mayweather agreed to a 30-month, six-fight exclusive deal with Showtime in exchange for $200 million. The deal could increase to $250 million for Mayweather depending on undisclosed escalators. Prior to this, Mayweather fought under the auspices of HBO and its PPV system. According to HBO, the nine fights that Mayweather fought with them generated $540 million+ in revenue from 9.6 million buys. But Mayweather was attracted to Showtime for the value added from the exclusive deal. It silos Golden Boy and Mayweather away from the HBO and Bob Arum contingency. The opportunity for elevated promotion appealed to the Mayweather camp (the money didn't hurt either).

It begs the question, how much money could Money Mayweather make if endorsements were added into the mix? Like Mayweather's other feats, the windfall could be record-breaking. Mayweather, by design, doesn't have a single endorsement deal.

"I don't feel like Nike has to make me. I don't feel like Adidas has to make me. I don't have anything against the companies, but my company is [The Money Team]," said Mayweather in a recent New York press conference. Mayweather's high-earning contemporaries in other sports vastly supplement their income with endorsements. LeBron James, for example, has an endorsement income of $42 million, which is nearly a 120% increase over is $19.1 million salary.

Estimating potential endorsements

Pay in boxing, like most individual sports, is contingent upon the annual success of the athlete. To this degree, athlete winnings serve as "salary" and naturally differ year to year. Mayweather doesn't always fight twice a year, let alone have huge paydays like with Canelo Alvarez. As stated, Mayweather supplements his fight guarantees with PPV funds because he owns the promotion company. This means that Mayweather's pay is sourced from many variables -- the larger the matchup, the larger the guarantee; the more PPV buys, the more commission.

Tumblr: Floyd Mayweather

After normalizing the figures a bit, let's conservatively say that with fight purse and PPV revenue, Mayweather averages around $45 million a year. Using logic from the LeBron example – if Mayweather, through endorsements, would earn 120% of his base – he would earn $54 million to bring his annual income to $99 million. Understand that this estimate increases with multiple fights, marquee matchups, and high PPV sales figures.

Richard Schaefer CEO of Golden Boy Promotions says that the Mayweather "is the greatest in the ring ever, but when it comes to marketing himself and exploring business opportunities, his skills are really unmatched." Still, consider that fellow boxers Manny Pacquiao and Vladimir Klitscho make $8 million/year and $5 million/year respectively. Is it fair to attribute the potential $54 million in sponsorship money to Mayweather?

Add this to the mix – the most lucrative athlete sponsorships come from apparel companies. For example, the NBA's Derrick Rose tops the Adidas roster with a $26 million annual deal. Nike pays golfer Rory McIlroy $25 million/year.

Mayweather brings added value; he already has built an apparel company, The Money Team, that retails in seven states. This could easily be extended to a Jordan/Nike type of deal where the brand is the crucial piece. The sponsor would earn revenue from apparel, equipment, and lifestyle sales, only adding to Mayweather's appeal. This could be fashioned as a lifetime deal like the David Beckham-Addidas agreement or a decade-plus partnership. In typical "Money" fashion, Mayweather would have options, buyouts, escalators, and other contracted adds. This does not account for the multiple endorsement deals that Mayweather would most likely pursue.

Endorsement $ per year

Athlete details

54 million

120% of estimated 'salary'

8 million

Manny Pacquiao, annual

5 million

Vladimir Klitscho, annual

42 million

LeBron James, annual

26 million

Derrick Rose, annual

25 million

Rory Mcllroy, annual

160 million

David Beckham lifetime

18 million

Andrew Wiggins, annual

Last look

It comes down to this: Mayweather brings a lot to the bargaining table. He is an undefeated champion, he is charismatic, connects with fans, and has an edge. Combine that with his attractive brand, his apparel success, and proven ability to shamelessly self-promote. From the above comparables, LeBron and Beckham have Mayweather beat when it comes to star power, no argument there. Pacquiao and Klitschko compete in the same sport, but the marketability of Mayweather is exponentially greater. Given that the unproven Andrew Wiggins locked down $18 million for a shoe deal before he even played a college basketball game, the estimated $54 million looks more than reasonable for the 45-0 battle-tested Mayweather. Not to mention he won't be selling just shoes, The Money Team brand will be extended to apparel, equipment, and overall lifestyle merchandise.

Regardless of the weight you assign to the above factors and speculations, Mayweather's personality, athletic accomplishment, existing apparel success, and overall marketability provide for above-average endorsement compensation.