I often post links to couples' stories in their clubs - that's the majority of the links I've contributed to Fanpop - and I also sometimes post more character-centric stories to that character's club if I come across a good one. I normally avoid adding more fandom-in-general/multi-ship stories though, because the fandoms can contain so many varying opinions that I couldn't be certain that fans would like them.

I also normally try to avoid linking M rated stories because of Fanpop's general approach to adult content. I'll only add an M rated story to a club which already contains other M rated stories posted by others - then I assume that club members are fine with it.

I don't know why I would. Hardly anybody comes to this site.

^I read fanfics linked in the clubs I'm a member of. And even in otherwise empty clubs I'll still add links, in the same way I'd still add images, videos and so on.