Floyd seem right, he is really popular, and anytime he fight he makes big money, we can't deny that.
In fact, Manny would not make the biggest payday of his career as a boxer if Floyd does not fight him, same goes with Floyd but this guy has been making big money already before he fought Manny. His name was even change from Pretty Floyd to "Money", because he literally makes money.
You can't really compare Floyd with the others. Floyd is an American citizen, and he has huge following among certain sections of the American society. The same can't be said about Manny and Conor. Manny obviously is popular among the Americans, but not as much as the native boxers such as Floyd. And that's why Manny tried hard for a rematch with Floyd. The only foreign boxer whom I have seen making big money in the US recently is Canelo Álvarez, due to his support base among the Mexican Americans.