A readership isn’t always static. Yes, there are some magazines whose readers stay with them for years (I am one of the original subscribers to Writers News magazine, gulp!), but there are also some magazines whose readerships change quite frequently.
When a magazine targets a particular niche readership the end result can lead to it loosing those readers! For example, the core readership of Photography for Beginners are … er … beginner photographers. These readers are buying the magazine for knowledge and to learn a new skill.
There will come a time when the magazine is not teaching them anything new and, as a result, they will look for another magazine to move on to for further knowledge and skills. So those readers will stop buying Photography for Beginners and move onto Amateur Photographer, or Digital SLR Skills, or one of the many other photography magazines. And then, after a couple of years, they may stop with that publication and move onto Advanced Photographer or one of the other professional magazines.
What does this mean for the writer? It’s important to identify these types of magazines, because the editor will be looking for ideas and articles on topics they’ve already covered before, possibly as recently as 12 months ago, although they will be looking for a slightly different angle. For example, a photography magazine might want a winter article offering advice to beginners on how to take photos of snow. The following year, the editor will be looking for another article about taking snow photos, because there will be a bunch of new readers who weren’t around when the last article was run, but it needs to be slightly different for those readers who did read last year’s article.
In some magazines, once editors have covered an idea, they don’t want to return to it for several years (the frequency of the publication also influences this, too). A quarterly publication rejected an article I’d submitted because the editor had recently accepted another article on exactly the same topic. I did mange to sell that article to that same editor at the same publication, ten years later, because enough time had passed for the reader (which had a low churn rate).
Of course, one magazine’s loss is another magazine’s gain, although it’s not quite so cut and dried if you look at the bigger picture. Magazine companies often produce a magazine for beginners, intermediates and more experienced readers, so whilst the readership might churn from one magazine to another, the company tries to keep the readers amongst its own stable of publications.