From what I've seen of it when an old topic gets bumped, the 30-day thing actually makes sense. We go through a topic, we discuss it until we reach a consensus--or run out of words, whichever comes first--and then we move on to other things. But you all see how our discussions go sometimes, they get long...not that there's anything wrong with that of course!...but most of us have the benefit of having read each post "as it happened," and we were all involved whether as spectators or combatants participants so we know how the discussion evolved.
Then we move on. Rinse, repeat, recycle; and the topic I just described gets older and older. Eventually we forget all about it; then all of a sudden, this ancient topic gets bumped back to the front page again. We of course open the topic to see the new reply, but it's a tossup about whether we remember the point of the topic or not. And that's even assuming the poster is answering the post directly above--but what if the new poster is actually responding to some minor point midway through the thread?
(And I mince no words when I say that most of the time, the "new members" in question seem to post a reply of minimal relevance to the original topic--a recent topic bump with a comment about the Gameshow Marathon episode comes to mind)
Then there's the counterpoint of "What if the new member wants to add something legitamite to a topic they're interested in?" There's no easy answer to that, other than to say "Search is your friend"--some of the posts by new(er) members tend to be duplicates of something that someone else has already said. I know that's kind of like saying a line of dialogue in your favorite show sounds like something you saw on another show just last week, and that it's not a solid justificationm but it's just how I feel.
