Top 4 biggest PPV sales of all-time in boxing

Ali
Foreman
Frazier
Mayweather
Pacquiao
Mcgregor

I believe Foreman was more famous than Frazier during the Rumble in the Jungle as opposed to the Thrilla in Manila. If this was FOTC I would put Frazier above Foreman.

By the time Mayweather and Pacquiao actually fought Pacquiao was slightly less popular than Mayweather I'd say ... And I know Mcgregor is huge in MMA circles and in the UK and Europe and even America but I'm not sure how famous he is compared to Mayweather and Pacquiao ..
I might be wrong about him it's hard to tell.

Mayweather never reached the level of fame Frazier and Foreman reached I'd say .... And just having their names associated with Ali increased their acclaim ... The lighter weight classes always take a backseat to the heavyweights ... And at his peak I'd say Pacquiao was more famous than peak Mayweather ... No clue about Mcgregor though

 

As mentioned Ali/FrazierI was promoted as 'the fight of the century,' a tired cliché for a fight to go with the other fights of the century we had, had (starting with Johnson/Jeffries). Like calling an exciting Aussie fighter The Thunder from Down Under, unoriginal, and of no real meaning, as it was so blasé.

At least 'The Rumble in the Jungle' was an original promotional title, albeit a terrible stereotype, even then.