Some comments, first to Roger: you pretty much got it about USD being worlds reserve currency and also mainly
why it seems to keep that status (for now). Some remarks:
- if/when foreign confidende in the USD tumbles, that money will start flowing back to the US in huges quantities. From a domestic viewpoint, that's hugely inflationary and it will hurt.
- google "Petro-Dollar". Some people go as far as saying the world reserve currency status of the USD is being "backed" by the US military. It's true to an extent: when Saddam tried to sell oil for EUR, guess what happened. Note that Iran is selling oil for gold to India now.
- A strong USD is not necessarily in the interest of the US. As James Rickards point out in his book "Currency Wars", the economies/nationstates of the world are in the process of a race to debase their currencies in order to help their economies by ways of improving exports... a death spiral.
I think as a currency bitcoin is of enormous value for the simple reason that you can transmit any amount you want instantly across boarders. That and the fact that its pseudo-anonimity and p2p base means it cant be shut down like previous electronic currencies.
I much prefer to call bitcoin a
money, or more specifically a
commodity money instead of calling it a currency. I'm not sure why, probably because currency sounds like: "some nations fiat currency".
I think the reasons for bitcoins success are manyfold. the 2 reasons cleanbit mentioned (works rather well as electronic payment system, can't be shut down easily) are important ones, albeit not sufficient for success. I would add: "has known inflation and known maximum total supply". Without that scarcity, bitcoin wouldn't have worked out.
And one more remark to Roger: yes, you're right, bitcoin has the first mover advantage and as long as noone comes up with any substantial improvement, it will remain
the cryptocurrency.