When you log on and see that no one is on, how long do you hang around for someone else to log in? I've seen Webchat quite busy a few times, but it seems like people just pop in for a second before getting impatient and leaving.
And you have to remember, it took a week or so for IRC to pick up any decent amount of activity after that 3 person limit was removed. Just give it time and have some patience.
If it makes any difference, I'm in there right now (though I might leave to watch a movie).