Everything is money that 2 or more people agree to be money.
Technically, as soon as someone would start to buy in the price would skyrocket and crash later due to lack of demand.
Well you can call it money, but if one has to pass up 1000 places to finally find a place that will accept the money, it's hardly an effective form.
Not all money are equal obviously, that's where the network effect comes into play. :)
