The two fighters are set to land a huge windfall when they take to the ring in August in a battle between the cream of boxing and MMA
Some have labelled it the fight of the century so far, while others see it as a joke and a stain on the sport of boxing.
What is certain is that Floyd Mayweather's upcoming bout with Conor McGregor, who is crossing over from mixed martial arts, will be one of the most hotly debated events of the year.
Mayweather is coming out of retirement to defend his unbeaten record against McGregor, who has become the UFC's brightest star since unifying its featherweight championship by beating Jose Aldo in 2015.