One thing I've noticed from time to time, during slower posting periods, is that no one knows what to do with their characters. That's when we'll get a bunch of threads that go "So and so sat down to eat lunch ((open))" or "So and so was at the bar again" or "So and so turned on the Danger Room for a workout".
These are all well and good and fine, and I'm not saying stop doing them -- just that they've been done a hundred times and are rather generic. Sometimes, even when they are joined, they peter out -- there isn't always something crucial happening over, well, lunch.
A possible alternative to those threads are, well, threads characters are interested in doing. Yeah, every character has to eat, but some characters can be found in the danger room, or the gym more often. Some characters might be trying to start a band, or are filming themselves jumping off of buildings and trying to become YouTube sensations. Some are exploring their powers, some are exploring their majors, and so forth.
I find that those threads can be awkward to start at times. It's easier to join in on those threads, if that makes sense? For example, if Trav were trying to push the Sam-Morrigan thing, it might be helpful if there were threads with people getting into physical fights! That's not something that Sam can really start as a post -- that's something that might work better if someone else starts it. That thread would be Sam-related threadbait. Or maybe Nailah and Hailey want to start a Blond Teen Detective-Slash Fighting Agency. They'd need other characters to come to them with problems to solve and/or punch.
This thread is for listing those kinds of things -- general threads you'd generally want to participate in on a general basis. Not a "this is something that I want to happen one thing", but rather "this is a genre of thread I'm looking to do".
It's also for people going "I'm bored; I want to do a thread. Aha! I see that Mad is looking for things Tosh can solve with science! I shall post a thread that needs science to solve," or "Hrm, my character has mental issues out the wazoo. Our psychatrist is looking for threads dealing with our many, many issues!". It's a database of "these are threads that people wanna do", that will hopefully be updated whenever someone changes their mind
Or maybe it's not for anything, it's your post, I'm not the cop of your posts
These aren't so much for major things -- not "so and so has a mysterious background and you need to investigate!" These are smaller things, like, "My character is looking for people to punch in the danger room" or "my character wants to have/force someone to try their cooking" -- things like that.
Maybe I should list some examples!