A thought experiment:
Imagine there was a base metal as scarce as gold but with the following properties:
-boring gray color
-not a good conductor of electricity
-not particularly strong, but not ductile or easily malleable either
-not useful for any practical or ornamental purpose
..and one special magical property:
-can be transported over a communications channel
If it somehow acquired any value at all for whatever reason, then anyone wanting to transfer wealth over a long distance could buy some, transmit it, and have the recipient sell it.
-Satoshi Nakamoto, August 2010