When I was in the US a few months ago, I noticed how few people seem to carry cash. Buy coffee, out comes the plastic. Buy a drink, out comes the plastic. Purchases of a couple of $$'s, all on plastic.
To me, it seems inconvenient to use a card all the time. Easier just to toss a couple of bucks on the counter than wait for a slip to sign.... But that's the way it is going there.