The inability for cryptocurrencies to do a transaction without an internet connection is a bug not a feature. Still, plenty of people go years without touching physical cash which makes up around 7% of the actual cash in the US. So it's not like Amazon.com or IBM have to use forklifts to move pallets of cash around. Better yet they can write a check for 100 million and the only transaction fee is the wait until the check clears.

PS: Sweden is down to 3% but we have a much larger underground economy which thrives on cash. Even more interesting MintChip is an example of a government backed anonymous digital currency system which supports USD. http://en.wikipedia.org/wiki/MintChip Which suggests cryptocurrencies may not actually make it.