In the last 6 weeks, IMQA has had 41,925 visitors. The average visitor views between 3-4 pages per visit and stays on the site for 4+ minutes. So people are looking around. Half of the traffic is new visitors, and Google is starting to send us a good bit of love.
The growth in between my mailers is all from visitors coming from elsewhere. Granted the user count isn't growing fast (yet), but there are a lot of lurkers who never feel the need to create an account.
I intend to work and baby this site until it reaches critical mass and takes off on its own.