Failing that, you need to either day trade Bitcoins and take advantage of the short-term price volatility, or make an extremely risky long or short bet on the long-term success or demise of the Bitcoin. Bitcoin is legal in nearly every country. If the merchant is using Coinbase, shortly after you send the payment, the checkout page will update to indicate that the funds have been received, and the purchase will be marked as complete. People also use Bitcoin to buy stuff online.