Companies, if companies held on to the Bitcoin they received (Dell,overstock,cheapair) and paid employees in it or used it for other services the price would be a LOT higher. Right now companies receive our bitcoins and instantly sell it for Fiat and raise the supply and demand can't keep up for it so that is why the exchange rate is lower.
Stop posting when you have no idea what you're talking about.
With that one it is not exactly and they are keeping already a nice portion of them
http://newsbtc.com/2014/05/02/patrick-byrne-overstock-com-10-percent-bitcoin-income-bitcoin/It's obvious that they can't keep it all just yet.