Bitcoin got a major new ally this week, as Overstock.com began accepting the alternate currency system as payment. Overstock isn't the first company to accept the currency, but it's larger and more powerful than previous companies like Reddit and OKCupid. Now Bitcoin users will be able to buy more conventional goods, from washing machines to coffee makers, giving a huge boost to the Bitcoin-only economy.

Bitcoin has come under fire from economists who see it as unstable on principle, but the move carries little risk for Overstock, which will presumably continue to do the majority of its business in more conventional currencies. In fact, since Bitcoin doesn't charge the standard 2% transation fee that a credit card would, they may even come out of the deal ahead. The bigger uncertainty comes from Coinbase, the bitcoin payment processor that's powering Overstock's latest move, but has never worked with a business of this magnitude. In a blog post announcing the partnership, Coinbase said, "we believe that Bitcoin is nearing a tipping point for broad consumer adoption, and we couldn’t be more thrilled to be working with the team at Overstock.com to help make that a reality."