Understanding the Economist

I've been reading The Economist assiduously every week for a dozen years or so now. It is a wonderful magazine, full of reliable information, expert opinions and analysis; and it is beautifully written, clear, witty and unrelentingly clever. Although it is impeccably edited and can almost never be faulted for bad style or typos, ever so often I would come across a sentence that I had to read over two or three, or several, times, before I could make sense of it. This happens with most densely written prose and I thought nothing of it, apart from enjoying later the satisfaction one feels when a difficult puzzle has been solved.

Recently though, either because something has changed at The Economist, or because I am in some sort of linguistic decline, I seem to be finding sentences whose meaning eludes me pretty much completely, even after several rereadings. The other day I came across this, for example:

Very few of HMV's customers only ever purchase music from HMV.

"Very few only ever do it"? What does this mean? For some reason, I can understand the very similar "Most of HMV's customers only ever purchase music from HMV", which I think means they never buy music from anywhere else. So I imagine the original sentence means that few customers never buy music anywhere else. But now that sounds strange. I guess the majority do buy music elsewhere. Maybe it means "Most of HMV's customers also buy music elsewhere."