Because of the way DAB technology works, broadcasters can transmit many more stations than ever before. Listeners in most major towns and cities in the UK can receive between 30 and 50 radio stations with a digital radio, in many cases that's more than double what's available on analogue. And it's not just more of the same - the content within that choice of stations is unique and exciting, delivering station formats that just don't exist on analogue. The FM spectrum is so clogged right now that there's no room for new stations that would expand listeners' choice with, for example, soul music, or country music, or big band swing, or any of the other 100+ brands that are available uniquely to DAB.
Because digital radio uses the spectrum more efficiently than analogue, it is possible to broadcast more channels using the same frequency, making room for broadcasters to expand their station portfolios.