Why this is the format most projects end up on
If you are printing a wedding paper, a school yearbook alternative, a zine or a conference handout, this is almost certainly the one. It is large enough to feel like a real newspaper rather than a folded leaflet, it runs up to sixty-four pages so it will not run out of room, and being printed on a traditional web press it has the soft, slightly absorbent look people actually picture when they say the word newspaper.
That press is the reason for both its strengths and its limits. Web presses are built for volume, so the cost per copy falls sharply as the run grows and the paper itself is genuine newsprint rather than a brighter digital stock. The trade-off is that short runs are less economical here than on the digital version of the same size.
The margin rule catches people out
Newspaper Club asks for fifteen millimetres at the top, the bottom and the outside edge. It says nothing about the inside edge, the one that disappears into the fold. That asymmetry is easy to miss and it changes the arithmetic: the printable height loses thirty millimetres, two margins, while the printable width loses only fifteen. Anyone who assumes a uniform margin and subtracts thirty from both ends up designing to a page that is fifteen millimetres narrower than the one they are allowed.
It is worth being deliberate about the fold regardless. Text running right up to the gutter on a stapled or folded publication is hard to read even when it survives the trim, because you have to flatten the paper to get at it. Most designers give the inside edge a margin anyway, whatever the printer permits.
Where it is the wrong choice
Two situations. If you want something pocketable or postable, this is a big sheet of paper and the smaller American tabloid sizes suit better. And if you are printing a handful of copies rather than hundreds, the digital tabloid at the same trim size will usually be cheaper, because a traditional press has to be set up whether you want fifty copies or five thousand.