There's a whole lotta things that em talks about that are cool amongst white kids but not with blacks, speaking generally of course.

Stuff like hating your mom, certain types of drugs like mushrooms, dressing up like a woman in videos, referencing trailer parks, referring to yourself as a 'mean cocksucker', just generally not acting 'cool' or suave, etc. I'd imagine a black artist that spoke about those things would probably have an abnormally larger white audience too.

It's kinda hard to describe but I think it's pretty clear to see. He rapped about things that were more relatable to white kids than other hip hop artists. He never really pandered to black people like Serch or V Ice. Although I checked out an interview he did with Howard Stern when he first came out and he was faking a 'black' accent/vernacular that was pretty annoying. He doesn't really do that anymore thankfully.