How can they sell GGG to mainstream boxing fans?

the old fashioned way, consistently putting his exciting style in against tough competitors on HBO.

 

I disagree. If all they get for Golovkin is foreigners like Proksa then this won't create any interest in the US.

Golovkin needs US based opposition to make it big in America, like Martinez or Chavez Jr. Geale won't work, neither will Sturm should he come back.

 

This.

Casual fans love KO's and undefeated records.

Also, he's a decent looking guy, which helps. He should definitety work on his english skills, though. He probably is right now.

 

Another ting-

If GGG wants to guarantee himself a unified title or two, and a shot at P4P status, he really HAS to work on his defense & movement. He looked better Sat night than perhaps in any other fight, but still a little stiff and exposed.

If he improves in this area, he will be even more fun / impressive to watch, which will make him even more marketable.

Then again, his current style is extremely energy-efficient. Perhaps that's part of his secret - He stays fresh in the later rounds while his opponent starts to get tired & sloppy.