I just found this thread so I'm gonna reply to it and hope somebody sees it. :) I'm actually surprised that there aren't more detailed responses to your question, KK; I would love to hear what methods have actually worked well for others.
I have a group game that I've GMed for a long time, and I've tried everything I can think of to drag in players. My game has survived because I've had a few players willing to stick with it for looong stretches of time. That's another problem, too, at least if you want your game to last for a while; not only do you have to attract players at the beginning, but you need to attract ones that will stick around and stay active. Many games who attract lots of people die out quickly when the people lose interest or get busy with other things. And because of that, you have to keep finding new players constantly, as replacements for the quitters, if you want the game to survive.
It's been surprisingly tough attracting players, and although I've had a game going for over a year, I still don't know what works best. I think it helps to be really patient, keep your expectations modest, and be tenacious about recruiting. As I understand it, bumping the recruitment thread is allowed *if* you have substantially changed or added to the content of the thread, so that maybe your new ideas will help attract people. My game has had, like, five or six recruitment threads with different pitches for the same game, highlighting different things about the game in an attempt to attract more people.
Incidentally, KK, I found this thread only *after* I PMed you an invitation to join my group game ... sorry about that! :) I honestly didn't know people find that sort of thing to be rude. (Do they really?) Cold-PM invites seems kind of desperate and therefore embarrassing to me ... but, I've been hugely flattered on the very few occasions that I've been PMed an invitation to a game, so I didn't think it was an impolite thing to do, as long as you're nice about it. I have found more than one player for my game using the cold-PM method, although most people simply ignore such invitations, or else express interest briefly and then never follow up.
Oh, one last thing ... I hate to say it, but it's just darn hard to get a group game started or keep one going for very long. I say that both from from personal experience and also from observation; if you look around, you'll see that compared to the number of recruitment threads, relatively few group games ever get off the ground; and of the ones that do, very very few last more than a month or two.
Anyways, there's my thoughts on the subject. There *are* numerous people at Elliquiy with really active and longer-lasting games, I'd love to hear their thoughts about these subjects.