I like your site, but I help run a vBulletin site so I'm biased. With all the activity your promotion is drumming up, you might consider a chatbox. We run one over at vfrworld.com and it generally gets a bit of activity. Sometimes we have to remind peple that they may get more replies if they post a thread to ask questions, but occasionally there is someone in the chatbox that can answer right away. We only allow registered users to use it so it gives some incentive to register but we have had pretty good success with it.