gloworm558 . <...> said:

Out of interest, I can listen to Play Radio in the car, walking down the
street, or in my house.

On what though? If it's a mobile then it probably cost a fortune

Not really. I've got unlimited 3G access for a fiver a month which means I can listen to anything I want whenever I want, as a by-product of having always-on internet access. The only enemy is battery power which goes down quite fast I notice if I stream (or use the Satnav!) for too long not plugged into an adapter / charger.