Where do they get their fiat from? One particular exchange? Several? Which ones? Do they trade right when purchases are made? If not, how do they deal with the price-swings? What about Bips, and others?
Boy, I bet those upward price-swings are killing them right now.
To address your main question, I'm pretty sure we're not privy to where or how they convert, but I will guess Mt Gox or BitStamp. As a company, they can't just sell them to anybody due to regulations, I believe. But, they can be to paid to a principle, whereupon s/he may convert, but now we're talking a tax nightmare.
Then again, I guess it may work if they convert using one entity who's business model is to do such that, akin to a one customer only exchange. Grey, but it might work.
I look forward to meeting Tony again in Las Vegas during the conference on the 10th and 11th.
~TMI
BTCITW