WBC/WBA welterweight champion Floyd Mayweather Jr.
WBC/WBA welterweight champion Floyd Mayweather Jr. of the U.S. speaks during a news conference at the MGM Grand hotel-casino in Las Vegas, Nevada September 10, 2014. Mayweather will defend his titles, including his WBC jr. middleweight title, against Marcos Maidana of Argentina in a rematch at the MGM Grand Garden Arena on September 13. Reuters/Las Vegas Sun

Floyd Mayweather made $14,800 per second and more than $2.5 million per round during his recent rematch with Marcos Maidana. Apart from his lucrative earnings, Mayweather beat Maidana via unanimous decision to retain his junior middleweight and welterweight world titles, securing his undefeated 47-0 professional boxing record.

During his last bout, which lasted full 12 rounds, the American boxer was guaranteed a $32 million payout but his earnings increased exponentially after the pay-per-view receipts were counted. Thanks to his own promotions company, the fight was aired on Showtime and generated tons of profit for the boxer.

In May, the 37-year-old Mayweather pulled down a guaranteed $32 million payday during the first Mayweather vs. Maidana fight but on the other side of the ring, Maidana took home a guaranteed $3 million payday for the 36-minute bought, which breaks down to a modest amount of $1,388 per second in the ring.

Thus far, there is no clear next opponent for the American boxer but his team acknowledged that the long-awaited Mayweather vs. Pacquiao fight is a possibility. But then again, Manny Pacquiao is set to face Chris Algieri in November thus the possibility of the Mayweather vs. Pacquiao happening this year is quite slim.

At this point, the Mayweather show appears to be losing its spotlight as manifested by the waning interest in his fights in the casinos in Las Vegas. Betting at MGM was down more than 50 percent compared to the Mayweather vs. Canelo Alvarez bout in 2013. In fact, the 37-year-old boxer was a minus-600 favourite over Maidana during their fight last week, which means that a bettor needs to bet $600 just to win $100. The odds, which might be driven by the lack of a suitable competition for Mayweather to face, can come across as scary to some people, according to ESPN.

William Hill, director of trading Nick described the betting handle on Mayweather vs. Maidana as "horrible," while the Wynn, Westgate SuperBook, CG Technology and South Point also pointed out that the Mayweather vs. Maidana action was light.

"No big bets; no accumulation of small bets on the underdog. No interest. Floyd's not the most popular guy," Hill further said via ESPN. "His fights aren't really exciting. People are tired of it."