[WillPS]

I could never quite work out which way that should fee - did BOX get more out of using the Kiss/Kerrang/Magic brands or do the Bauer brands benefit from being associated with a TV channel?

I would suggest it is the former. The music channels are less known than the radio stations, perhaps with the exception of Kerrang which has basically been all but killed off as a radio station (but in any case both are less known than the longrunning magazine).

That's not to say there was never synergic benefits in both directions, but even those deplete with the severe reduction in audience.