It's doing fine on UK iTunes. I don't understand why some radio stations hasn't playlisted it there yet.
In UK radio for post-album singles 'impact date' is used. It shows when approximately song's maximum airplay should be reached. Radio 1 the most important radio station in UK always follows it. The label probably wants to set 'impact date' when Brit Awards airs and Katy performs so DH could reach better peak position.
