"Think a lily-white Stanford graduate would see a market in top up cards? I bet you they wouldn't!"
Maybe you don't realize but your comment is quite racist. So, you think by virtue of being black, every African-American somehow has an inherent understanding of African nations.
Here's a excerpt from Jumpa Lahiri's book The Namesake about similar sentiments for a second generation Indian-American man talking to friends of his white girlfriend about getting sick while visiting India:
"But you must be lucky that way"
"What do you mean?"
"I mean, you must never get sick."
"Actually that's not true," he says, slightly annoyed... "We get sick all the time. We have to get shots before we go. My parents devote the better part of a suitcase to medicine."
"But you're Indian," Pamela says frowning, "I'd think the climate wouldn't affect yo, given your heritage."
"Pamela, Nick's American," Lydia says ... "He was born here."