(CNN) The boxing purists are utterly dismissive of the fight as a total mismatch but the fans seem to love the idea, turning out in their tens of thousands just to glimpse the fighters on their promotional tour.
And the increasingly probability is that when that peerless old boxing master of defense -- Floyd Mayweather Jr -- meets the young Irish mixed martial arts prince -- Conor McGregor --- on August 26 in Las Vegas, it'll turn out to be the most profitable boxing match in history. Well at least for a month or so.
Mayweather, who has always liked talking money and is liberally rounded with his figures, told me that he expects to make $300 million (to add to his $800 million career earnings) from this -- his last fight. McGregor says he expects to "quadruple" his net worth.
No wonder Mayweather's long-time business partner, Leonard Ellerbe, has been beaming like the proverbial "Cheshire Cat." Business is looking very good. This is a fight -- so the promoters say -- that the fans demanded and it is evidently selling.
About 10,000 fans turned out at London's Wembley Arena on Friday, largely to see McGregor and salute him on his 29th birthday.
It was a carnival atmosphere -- lots of Irish flags to welcome the former plumber's mate from Dublin -- as well as masks and T-shirts bearing the image of their open-mouthed bearded hero.
A lot of beer was quickly drunk. Noise levels rose -- piped music and crowd singing -- long before either fighter was ever seen.
To a man, they all seemed unperturbed at the prospect of paying $99.95 to see the fight in high definition on pay per view television.
One man had flown over from Dublin just to see McGregor strut his promotional stuff. A friend had already secured him a $2,000 seat (one of the cheaper seats) for the Las Vegas bout.
They just love their man and think he has more than a puncher's chance. Another fan was going to bet heavily on McGregor. He wouldn't say exactly how much, quickly adding "as much as his wife would allow."
McGregor's unshakeable self-belief is clearly infectious. And as the fans all know -- and as the Daily Telegraph boxing correspondent Gareth A Davies put it -- McGregor didn't "just kiss the Blarney Stone, he swallowed it." He can walk the walk and talk the talk.
Mayweather and his entourage needed three 12-seater jets to ferry them around -- from Los Angeles to Toronto, then to New York and finally to London. McGregor and his team had to make do with just one jet.
Almost everything about the tour was predictable -- loud rap music to introduce the warriors, a bit of dancing and posturing by each of them and a welter of expletives. Hardly two sentences were uttered without use of the F-word.
And to ensure perhaps that the media continued to pay attention they cranked up the racial and sexual insults as the tour progressed.