This is the fundamental problem with all non-fiat currencies and is why the world moved off the gold standard
The utility of the currency will depend on how many vendors ultimately accept it. And during the growth phase the number of vendors also increases exponentially. For the very same reason it doesn't make any sense to spend the currency during this time it makes a lot of sense to accept the currency during this time.
The reason a lot of us have invested in BitCoins at this stage is that we believe the growth phase will be followed by a stable phase, where adoption has reached an equilibrium or a saturation point. It is during this phase that the coin becomes a currency which makes sense to spend, and its utility as a currency can be realized.
We may be wrong; we may be right. Currencies have always been issued by governments before now, and up-start currencies have only really been possible since the advent of the Internet. Economists have never really had a chance to study a currency growing from $0 value in real time as they have had with BitCoin.
That's far from guaranteed.
Gold started off as a commodity, worth much more than nothing. It ended up being a means of exchange because its properties are suitable: it's highly valuable, easily divisible and durable, and other stuff I forget now. But those are the reasons it started being used as money.
In fact, it's possible that nothing that will be widely used as a currency in the future will start off at zero value.
Bull. At this moment, I'm issuing an AqueousCoin to your pessimizer-account. In order to spend it, all you have to do is prove your identity by logging into HN in front of me or in front of a notary public, and I will send you $1 (minus postage.)
Done?
Sometimes (or possibly always by definition) the vendor comes before the currency.
I suppose that's kind of an epistemic question. But to me, since how much someone buys something for is the central determinant of its price, it's not worth that price until someone buys it for it. So, perhaps it isn't even $0. The price of my AqueousCoin is (undefined)
Recent counterexample: The Euro started off at about $0.80. From the moment it came online, it had some intrinsic value because of its status as legal tender in the eurozone. That meant that it was essentially guaranteed that from moment zero, there was some non-zero rate at which people with dollars were willing to trade them for euros.
The only currencies that one should expect to start off at $0 are completely un-backed ones such as cryptocurriences.
If you create a currency from scratch, and you are not a representative of some country or corporation, it's only ever going to be worth $0 at the beginning. But in both cases it's the people who buy it who decide what it's worth.
I suppose this is just quibbling about minor details, but what the hey. The euro is, by definition, the official currency and legal tender of the eurozone. If we're going to count the essential characteristics of what something is as extrinsics, then we've wandered off into some epistemological bizarro-world where you can probably get away with whatever you want about anything.
Its officialness gives it two extrinsic qualities: 1) It can be used to pay taxes in some countries and 2) It is unlikely to be outlawed.
To me 1) is not special. In my view this just means there will always be at least one vendor that accepts the US Dollar (the US government) and while that's a nice guarantee, it makes the dollar different only in degree, but not kind, from BitCoin.
2) is slightly more interesting because it means that while Bitoin may be outlawed, the dollar will most likely never be outlawed, and the current regulatory framework governing money transfers, financial reporting, etc. is likely to stay consistent.
I believe BitCoin will be regulated more heavily, but not altogether more heavily than the dollar, but it will be not outlawed. Thus I think BitCoin in the end will not be meaningfully different from other fiat money, but it will offer things that fiat money can't offer, like unlimited electronic transfers over the Internet at small cost.
Of course, like anything I don't know the future. Here's to hoping.
Cryptsy, for example, makes a market in more than 70 crypto-currencies [0]. If there's a low barrier to creating new currencies, then is the supply really limited?
And it's not too hard to picture intermediaries, like bitpay and coinbase, to support many of the alternative currencies... helping adoption immediately.