larks35, I hide topics so they don't show in active, as then I get more of what I to see.
If I have say ante natal, style & beauty, ebay, holidays, book club, products, etc etc not hidden, then a large % of those will show up in my active convos, pushing out more relevant-to-me threads.
Whereas, if I hide them, I get more chance of seeing the topics I do want!
So it isn't a matter of just not clicking/posting is is about optimising active convos for your needs.