They can sell on their own market too? All money that's trasnfered to them for use on their site they hold but can't use for paying bills obviously, so they can just fill buy orders and free up the help USD for use in the company if they wanted too. I doubt they'd do it all at once as then they'd drop the market price and get less compared to doing it in small amounts, that and I doubt they'd let the business get to a point where they'd need to this in any scale anyway.