I just found out that you can pay for Wuala with Bitcoins. They are owned by LaCie, who have a revenue of €351.8 million according to Wikipedia. I think this makes them by far the largest company to accept Bitcoin for payment. Is that correct or are there other big players in the economy?
It is fantastic to see companies accept Bitcoin, even if it is just an "alpha / trial" like the method Wuala provides.
While Lacie (Wuala) is likely the largest company to accept bitcoins directly as payment, that is a specialized product of interest to a smaller subset of the bitcoin community. Their volume of bitcoin commerce probably is a fraction of that for other bitcoin businesses which are needed by a wider customer base. The larger dollar amounts where bitcoins are used directly for purchases might be in categories such as web hosting, dedicated servers, anonymous VPN, etc.
The largest companies to benefit from Bitcoin commerce though are the companies that offer vouchers or e-gift codes that can be used for payment. These include NewEgg Vouchers (purchased on BTCBuy.info) and Amazon Credit and eBay Gift Codes (purchased on SpendBitcoins.com). Those are, by far, where the largest amount of Bitcoin commerce is occurring. Some day these companies will simply cut out the middle man and start accepting bitcoins directly (or through a payment intermediary such as Bit-Pay).