Its seems that some white women don't really care bout the size but are turned on more by the fact that the guy is black and the idea that black guys are bigger. Because I've seen white women say a guy has a BBC and he really was just average or below it. I think a black guy with a small penis would have more problems with black girls.
I agree with this and Long Dong's reply in that there is a lot more that most white women find attractive about going Black. It's just unfortunate that so much emphasis is placed on size.
The really foolish thing about it is that most women can't handle a really large dick. Even in porn, where you would expect the women to be experienced enough to take a large cock, usually a third of the guy's dick is still out her when he bottoms out against her cervix. He can forget about getting a decent blow job too, since most women have trouble getting much more than the head in, unless he isn't very thick. Don't even think about anal, just the though makes most women run.
Sometimes being average is a good thing!