The style, attitude, and demeanor of the Klitschko's make them less likely to be massive stars here in the US. We are the country of icons of sport legends: Ali, Tyson, Louis, Jack Johnson, Rocky Marciano....those are the guys with the styles and the substance to capture the entire nation. Wlad and Vitali have too much respect to act in the manor that Floyd Mayweather Jr. or Roy Jones Jr. act, and their fighting styles don't make up for it. Americans have short attention spans and it takes constant action for the non-boxing majority to be intrigued, they need lots of bells and whistles and the Klitschko's just don't have those bells and whistles.