Yes, it is. But it is the same thing you do when you "pay" in for example $ for euros. When you "buy" euros with any kind of exchange what do you buy? Notghing? BTC is another, relatively new, kind of exchange. When/if you buy 1 BTC for 899$ you can sell it or any portion of it for any kind of exchange: Euros, gold, services, alt coins I hope this helps. Best whishes.