@ Pen-y-gors - of course it's a bubble, and could burst. But some bubbles can outlive us all. Most obvoiusly, gold, whose financial value has far exceeded any intrinsic value for millennia.
@ratfox - social experiment. Hmmm, well it's not without precedent (as has been pointed out). But a new concept with zero intrinsic value? This is most interestingly a commentary on fiat currency. Viewed like that, it's an intrinsically better store of value than something the Emperor[1] can just print more of whenever it's expedient.
[1] A reference, if you like, to the sub-plot in Goethe's Faust where Mephistopheles invents Fiat currency just when the Emperor is desperate, causing a devastating bubble.