Thanks for giving your insight Rok, Thufir, and Envious! It really does sound like the two most important things to a post getting read, at least by males who seem to be the only ones chiming in, are the title (descriptive and/or intriguing ones) followed by the ideas themselves or possibly even the O/Os.
Something else I didn't even think to ask about
-Does the number of views and/or the number of replies impact your likelihood to click on a thread?
I generally avoid posts with lots of views. Like you mentioned Thufir, for me a lot of IM rp is about instant gratification; A lot of views and replies makes me think the person will be too busy to rp. Even long term, a person who is very popular is someone I don't want to rp with because inevitably they will get distracted from any plots in fairly short order.
Also, thanks to you all I think I've realized the last tact I took with an rp wanted thread was bound for failure. I assumed I could draw more interest by having a title targeting the segment of users who have time constraints. It now seems like time constraints aren't a major factor in shopping around for roleplays. If you're looking for IM rp already, interesting ideas and O/Os come first and time issues can be worked around.
And Bandit, I think you might have convinced me to, cautiously, start to see if a couple targeted rp plot suggestions to users based on their O/Os might pan out.
I've also been tempted to start a new rp wanted thread with a title like "4 plot ideas from fellow elliquiyers."And involve other players in brainstorming a few ideas. I dunno if crowdsourcing fun plots has ever panned out before though hehe but it would be something a little novel at least ;p