In terms of coverage, all I know is it was on about 5 stations in the Midlands, no idea how many people heard it, but there were NO hits on my soundcloud as a result lol. Go figure!
Haha, but if you think about it, it totally figures. If I hear a song on the radio, I don't need to seek it out on soundcloud. And, if I want to hear it again I can call up the radio show on iPlayer. This works really well if I've forgotten the name of the song or artists (which I do a lot).
As for BBC introducing, I think it's a great thing. But you'd be naive to expect anything from it on its own. Cathy and I uploaded our song to introducing and to Tom Robinson's Fresh on the net blog. We were selected, and chosen as one of that week's favourites, and as a result we were played on BBC6 music - once as part of a Tom Robinsons mixtape, and once on his main show.
Didn't get any hits on soundcloud at all - what did get us plays on soundcloud was being featured on blogs (which took a LOT of emailing and schmoozing generally).
So as part of a distributed effort, I think introducing can be great for giving you extra credibility. But it won't get you anything on its own apart from a very modest PRS payment :p