That will be interesting when it comes time to sell all that revenue to pay their supplier.
If I had to guess, I'd say that they'll pay their supplier with cash from an investor or a loan. Then they'll liquidate the BTC slowly over time, perhaps using off-exchange services such as "fastcash4bitcoins.com". Their employees will probably take a significant portion of their income in the form of bitcoin. I wouldn't expect them to try to dump the entire bitcoin balance on MtGox in one day.
I don't think they keep all their cash in bitcoins. It'd be too risky if the price dropped they'd loose a significant amount of money. They probably pay all their bills and some of their employees in fiat so they always need it on hand.