The only thing the six-fight, 30-month deal he signed with Showtime will unquestionably change is his payday.
The guy's already known as "Money" because he's the world's highest paid athlete, according to Forbes. But after signing Showtime's massive deal, Mayweather may want to consider upgrading his name to "Mega-Money."
"He was already, by far, the highest-paid fighter in the world," Mayweather Promotions CEO Leonard Ellerbe said. "This is going to take him to a whole other level."
In 1990, promoter Don King pulled a similar move when he engineered Mike Tyson's exit from HBO and convinced the former heavyweight champion to sign a lucrative deal with Showtime.
Landing Tyson in those days was like getting a license to print money. Even in a universe of addressable pay-per-view homes that is barely half what it is now, Tyson has four of the five biggest pay-per-view bouts in history and six of the top 10.
The success of those pay-per-views made Showtime a lot of money. A little more than 20 years later, Showtime is taking a similar kind of risk and expecting a similar outcome.
Showtime Sports general manager Stephen Espinoza brokered the deal with Al Haymon, the unseen and unheard adviser who cemented his reputation as boxing's most powerful figure by completing the biggest free-agent signing since Peyton Manning went to Denver.
Espinoza said Mayweather's presence on Showtime's roster won't impact its regular boxing business. Mayweather's deal is essentially a pay-per-view deal, though Espinoza said there is a way that Showtime could "get creative" and have a Mayweather fight on CBS.
HBO sources said they were offered the opportunity to match the deal, but passed. This was the second time in two years HBO saw one of the sport's flagship fighters leave for its fiercest rival.
In 2011, Top Rank took Manny Pacquiao from HBO to Showtime for a fight with Shane Mosley.
When that happened, there were plenty of long faces inside the HBO offices. The Pacquiao deal Top Rank chairman Arum had negotiated with Showtime was presented to HBO and HBO executives admit they could have matched it.
But there was a high-stakes game of chicken going on then and the truth is, the HBOers never thought Arum would follow through. When he did, it crushed morale inside of HBO.
That did not appear to be the case, though, when HBO passed on the opportunity to match the Mayweather deal on Monday.
"Pay-per-view is such a crazy business and that was so much money," an HBO source said.
Two sources said that in essence, Showtime is guaranteeing Mayweather a minimum buy rate, meaning that Mayweather would have no risk. Neither Espinoza nor Ellerbe would discuss the particulars.
"This is a very complex, detailed deal, and we all agreed that it was best that we didn't discuss any specifics publicly," Espinoza said.
Luring Mayweather from its archrival gave Showtime a major property that, in some ways, could serve as a loss leader. Espinoza, though, said he expects the deal to be profitable not only for Mayweather but for Showtime.
"We don't have the luxury of making deals that don't make sense in and of themselves," Espinoza said. "I wouldn't mortgage away the future for a short-term gain in visibility. What we made was a very aggressive, creative proposal that was very attractive to Floyd and still makes sense for us.
"It allows us to showcase the top fighter of this era through a variety of different programming while at the same time building and expanding his pay-per-view performance. Yes, it was an aggressive deal, but it was still a prudent financial arrangement for us, as well."
The deal hardly puts HBO out of business, as some have suggested in the immediate aftermath of Mayweather's announcement. The downside for HBO is that its biggest source of talent now is Top Rank, and Arum has always been difficult to appease.
Arum now has plenty of leverage with HBO, and all of his fighters are on fight-to-fight contracts. The significance of that is he can move any of them over to Showtime at the first sign of any trouble with HBO.
Showtime would love to steal the likes of Nonito Donaire, Brandon Rios and Gennady Golovkin, to name a few, away from HBO.
Arum has had a strong working relationship with HBO's new leadership team, particularly HBO CEO Richard Plepler and Michael Lombardo, the president of HBO programming, and that has to help HBO's cause.
Arum wouldn't rule out bringing a Pacquiao pay-per-view event back to Showtime even though Espinoza and the promoter aren't currently on good terms.
"Never say never," Arum said. "Ultimately, I have a responsibility to Manny to do the best deal I can for him."
The knowledge that their boxing business now depends so heavily upon the mercurial Arum has to make HBO executives more than a little nervous.
Assuming they're able to do that – and that's obviously a huge assumption, given the history between the sides – things on the non-pay-per-view level won't change appreciably.
Golden Boy and Top Rank have the two deepest stables of talent among U.S.-based promoters. Golden Boy supplies Showtime with the vast majority of its fighters, and Top Rank now does the same for HBO.
HBO could get burned if it loses Adrien Broner, whom it has been grooming as Mayweather's potential successor the last two years. Though Golden Boy CEO Richard Schaefer said Tuesday he's willing to negotiate a long-term deal with HBO for Broner's services, moving him to Showtime would essentially make Schaefer's job easier in that he'd be able to plan long-term better knowing all of his key athletes would then be with Showtime.
Showtime and Mayweather unquestionably shook the boxing world with the deal on Tuesday.
As long as HBO Sports president Ken Hershman and Arum can stay civil, the biggest impact of Tuesday's deal will be, as it often seems to be, on Mayweather's bank account.