But, what do you do if you start up the game and it winds up that no one is interested?
Sometimes advertising a new game ends up being just an opportunity to learn (a) patience, (b) how to deal with disappointment, or (c) both of the above. It's truth no one would like to hear, but it can still be true.
As for strategies to help avoid that unfortunate situation... I am not sure. But a few things you might try are:
1) As you already have worldbuilding threads, mention your interest check there and keep those threads active. Not everyone checks out all worldbuilding threads, but someone might.
2) Put something about it in your signature.
3) Contact people you know and tell them about your game. You have been around a while so you must know a few people you would like to write/roleplay with. If they have their plate full, ask them to post that in your thread, to leave a "would love to play if I had time" message. There are limits to how much and how often you can bump your thread, but there is no rule that I am aware of that forbids you from using "surrogates" to give your thread a gentle nudge now and then. It will also tell people that you are trusted to run a game.
4) Also keep in mind that you can't simply bump a thread regularly, but you can add to an interest check if you add something new to the thread. You can't just bump a thread, but you can strartegize your ... "information dispersal", so to speak.