If gold is valuable, then $COMMODITY is valuable.
set $COMMODITY = my poo.
Hmm, your formula doesn't seem to be working.
I chose $COMMODITY on purpose. Not $ANYTHING_YOU_LIKE. If your poo becomes tradeable, then it becomes a commodity and my "formula" would be true.
As it happens, you picked a bad example. Excrement does have uses, and therefore has value to someone.
My point is, and has always been, that there is nothing special about gold. Any argument one makes to say what it is that makes gold valuable will apply to other things too. The only one that doesn't is "gold is the only thing that is gold"; and that's just a circular argument, so tells us nothing.
But I agree with your argument that bitcoin has value. Gold is valuable because it has valuable properties (unlike my poo). Bitcoin is valuable (or not) according whatever properties it holds (or does not). Gold and bitcoin share certain properties, but they are not entirely identical. We should start talking to goldbugs by first telling them about the properties bitcoin shares with gold. Then, when they agree on those, educate them about bitcoins unique properties.
Agreed. I didn't mean to imply that I think bitcoins are gold. What I mean is that whatever the useful subset of properties are that gold has that makes it valuable are the same properties that make bitcoin valuable. Bitcoin, in my opinion, has additional properties, but I don't think that matters for comparisons with gold.
This example also explains how to take over bitcoin with another digital currency. Start by making the currency backed in bitcoins, and give it some unique properties (e.g. instant transaction confirmations, better payment support, w/e). One-day you realise people don't bother converting their new currency back into bitcoins...
I anticipate that once digital, distributed currencies become normal, that this is how competition between them will occur. One advantage that is often missed about Bitcoin (and subsequent currencies) is that it will make competition between them very easy. It will be so simple to switch between these electronic currencies that people will switch to the one that suits them best. We'll all benefit from that, as we'll end up with the best rather than the best compromise.