I disagree that it helps as far as marketing to being white and American. Same goes for blacks. Look at Kelly Pavlik. Dude has had some worse HBO ratings and worse
HBO PPV ever. Black fighters are a hit and miss. IF your exciting KO artist, it'll sell yourself. If your a black slickster, ain't selling no PPVs. To me, being Latin American is tops in todays boxing as far as markability.