@datafish, what kind of product or service would that be? Is it truly unique? I think I've seen everything you can possibly call a product or service, and nothing is unique in the sense that all of them are merely variations of something else.

Therefore, there would always be some sort of fiat valuation of it.

Unless you have a completely new invention.

Or you are selling alt-coins.

So how much are the alt-coins worth? What if, instead of buying a product or a service, I trade my BTC to buy LTC? When you open that up, you can also trade BTC for any of the literally hundreds of other coins (no matter how worthless.)

Now, I understand LTC has a price in USD. But most of the other coins do not directly have a fiat price. They are mostly pegged to the bitcoin.

A popular alt is DOGE. It does not have a fiat exchange as far as I am aware. I think LTC has a lot of exchanges available. One of the larger ones is BTC-E, and that does have some other fiat / virtual currency pairs.