Classic magazine theory states that mags work by developing a bond with the reader, becoming, in effect her or his friend. Lately this has been developed into the idea of fostering a community around the title (or brand, if you must), all of which seems to work pretty well.
But at what point does clubby become cliquey?
The thing about communities is that they are great when you are on the inside, but horrible when you're on the outside. If the magazine-reader relationship can be characterised according to the friend/community model then there is a real possibility that individual readers may, at a given point in a magazine's development, feel frozen out, no longer part of the charmed circle of like-minded chums.
And if publishers refine their reader research too far not only may they become very vulnerable to the whims of trend (which I believe may partially account for Max Power's circulation plunge), they may also make non-core readers feel less welcome than before.
The question then becomes, is it better to have a less focused magazine with a larger casual readership or a very tightly focused magazine with a dedicated core readership and very few casuals?
Aren't you glad you're not a publisher?