I believe that's what Sid was getting at. He did increase the population of the Pub while he was a mod.
Just to comment on a few things here.
The Arena has always been a rather low-flow room and I wouldn't expect it to be the poppin' place to be just because the OOC presence is gone, but at least when I started to strictly enforce the OOC rules in the Pub (and since I was there all day anyway, I started to RP a lot more) I saw a noticeable jump in user population and role playing. During my short tenure the Pub went from about 6~ people on average to 15+, often topping out at over 20 people during prime time hours (night time EST) and into the early hours of the morning. This is purely anecdotal, but it's my belief that by keeping the OOC/cliqueishness to an absolute minimum and then fostering RP, more people are inclined to check out the room and, more importantly,
stay in the room. The constant nuisance that is the OOC is gone, and stops driving people out.
So my advice is, if you want to see the Arena grow in popularity, foster new roleplay and don't scare the new blood out by being assholes and talking all the time and disrupting the flow.
I agree with this. The cliques were getting very damned annoying.