Founded in 2011, while Bitcoin was still in its infancy, BitPay was created with the intention of making it easy for businesses to accept bitcoin payments. NewEgg, Valve, and Microsoft, to name a few, use the service to extend the payment options displayed on their sites.
BitPay accepts bitcoin on a retailer's behalf, and pays them the equivalent in fiat currency, typically U.S dollars. The company is currently the largest bitcoin payment processor in the world, serving more than 60,000 merchants on six continents.
http://bravenewcoin.com/news/bitpay-extends-exchange-services-with-visa-debit-card
