Now Bitcoin can't serve as a medium of exchange in some small towns, but there are many places where it's accepted. That proves Bitcoin has a big potential to become "real money".
Actually, there is no way for bitcoin to become real money unless it will become fiat. It is a digital currency that can transfer wherever you are. Why it cannot serve as a medium of exchange? Wherein fact you can use bitcoin in all places, as long as you are connected in the internet. Bitcoin will become the single monetary currency in the future because its easy to use and popular that brings decentralisation and transparency to the world.