Terrestrial Radio, people still listen to that?
Over here, across the pond, some of us do something that most in the UK probably cannot fathom: we pay for radio.
It's called satellite radio (Sirius and XM). Why do we pay for it? No commercials on the music channels. That's right, I can listen 24/7 and never hear a single commercial. There are channels dedicated to whatever genre of music you want. On my trip to Britain last year I had dozens of hours of precorded sat radio with me. I tried listening to the local stations from time to time, but after getting used to zero commercials, I didn't last long before switching on my sat radio.
I realize the UK is a different market, covering the UK with radio is vastly easier then North America due to your higher population density. That said, IMHO, the days of commercial radio are numbered. If there was a service available in the UK (be it terrestrial or satellite based) that offered completely commercial free music, would you pay for it?
FWIW, DAB exists here in Canada, barely. It came out a few years ago with huge fanfare. I actually bought a receiver, it's reception was beyond horrendous. I returned it a couple days later. The problem DAB has is it has pretty much no advantage for the consumer over FM. Even if it's reception were perfect, the sound quality is no better then FM. Battery life could eventually come close, but it's doubtful it could beat FM.