The idea sounds nice since it would seem fun but the practicality is very low if any, You can easily exchange BTC for USD in a short period of time using exchanges or in peer to peer deals, Physical shops for things like movies etc... are finished because of the internet so don't a digital currency would need a physical shop.
I think that what happens is basically all. Earn bitcoin and then sell it for dollars to buy something in the shops because bitcoin is not a popular currency.