From some of the great rps I've participated in, the GM never revealed any secrets to us outright, rather made clear what the goal was for the group to accomplish, that way it kept everyone on track, avoided speed posting, and everyone knew how to move their characters along. Such as, have all characters get from point A to point B in their posts. And when it came to suggesting key points in the plot, they would make tiny hints in the OOC. Very obscure hints, leaving us to wonder what the next post would entail. I've noticed that this keeps the interest of the players equally gauged for the duration of the rp. Just a tip from my extensive years of role playing.