I don't think it's possible that someone who is into football (even soccer) doesn't know who Del Piero is. He's just one of those stars with truly universal fame.
No, what I meant is that the public in the US won't be attracted by Del Piero, unless they are of Italian heritage. Beckham was a pretty face from the EPL, Henry was from the EPL. The majority of the small number of football followers in the States are EPL followers, I guess. The Latinos would be attracted by La Liga players and a serie A stars would attract a crowd only among the Italo-Americans.
Just a logical assumption, which might not be true at all, I guess.