Floyd Mayweather: Unbeaten and unpopular boxing champ

None of the criticism appears to matter to Mayweather who plans on playing Andre Berto on Saturday in his final fight

LAS VEGAS: Ask Floyd Mayweather if he would prefer to be popular or successful, he would have to say the latter.

Americans love a champion: but they don't love Mayweather, despite him boasting a perfect 48-0 record that has seen him unofficially crowned boxing's pound-for-pound king after a decade of domination in the welterweight division.

With that success -- and thanks also to his business acumen -- has come immense fortune: he is the world's highest-paid athlete with earnings this year of $300 million, according to Forbes.

For many people, that is where some of the problem lies: it is not that he earns bucket loads of money, it is that he flaunts it.

Follow Mayweather, 38, who says Saturday's bout against Andre Berto will be his last, on social media and you are treated to a weekly rundown of pictures of his cars. Or suitcases packed full of cash. Or his latest shoe-shopping expedition.

Read: Andre Berto is the fall guy in Mayweather boxing circus

On September 1, he posted a black-and-white photo on Twitter of him posing with three sports cars and a private jet, and the caption: "When I'm in the air, it's private. When I'm on the ground, it's foreign."

When I'm in the air, it's private.

When I'm on the ground, it's foreign. pic.twitter.com/GgsRyBRfgh

— Floyd Mayweather (@FloydMayweather) September 1, 2015

Twitter users' comments to the photo are telling. Some are positive, many more are negative -- and a few are too rude to print.

"This man has no limits," wrote one, and another: "And when you hit women it's domestic."

@FloydMayweather @JODYHiGHROLLER And when you hit women its domestic.

— Sean (@KentuckyKroge) September 2, 2015

That is the other reason why when Mayweather takes on the hugely unfancied Berto in Las Vegas the underdog will have the support of the MGM Grand and the pay-per-view audience at home: Mayweather has spent time in prison for one of a string of domestic violence incidents.

None of the criticism appears to matter to Mayweather, a father of four who has spent most of his 19-year boxing career fending off flak, even sometimes from his own father, also called Floyd.

"Nobody's forced to watch. Watch if you want to watch. If you don't want to watch, don't watch. Write about it if you want to write about it. If you don't want to write about it, don't," he said recently.

"I'm not saying if you write good or bad, just continue to write. Keeps me relevant."

Tellingly, some of Mayweather's most ardent supporters are from fellow boxers, who respect his supreme fitness, work ethic, athleticism and boxing brain.

Read: Woman football coach will be Mayweather's guest at fight

"Floyd has been icon for some time now," Berto told reporters ahead of the bout, crediting Mayweather with being "crafty" in the ring, although he agrees with experts who say the world champion is showing signs of age, allowing himself to be caught more often with shots.

"He's definitely showing some slippage throughout the years," said Berto.

"But he's one of those guys who doesn't abuse his body and he's always respected the sport.

"So it's not taken too much of a toll in the ring and he's not really abused himself out of the ring."

Ivan Goldman, a novelist and writer for the boxinginsider.com website, is not nearly so flattering, branding Mayweather "not a great role model" and "a jerk."

"But I think that he understands -- and the people around him understand -- that he's hit on something here by being the villain," said Goldman.

"I don't know that anyone has taken a poll, but quite a lot of people buying his fights are hoping to see him lose.

"It's almost like professional wrestling: sometimes the villains make more than the heroes."

Mayweather's critics are also damning of his overly defensive style -- the last of his 26 knockouts came in 2011 -- and accuse him of dodging the most dangerous opponents simply to embellish his record.

Goldman recognizes that Mayweather boasts sublime defensive skills, but that means he is no crowd-pleaser -- his May defeat of Manny Pacquiao was billed as the "fight of the century" but was widely viewed as a dud.

"Floyd is a non-aggressive fighter and his fights are generally not terribly entertaining," said Goldman, adding he won't be forking out to watch the bout on pay-per-view.

"They are not terrible fights, but they are not good ones and they're not worth paying extra to see."