Great site, but like most forums, 1/2-3/4 of them are likely non active members (do not log in or have ever posted). I admin another forum online and we use to have a few thousand members. We decided to check to see how many actually visit the site. Found half had signed in once, looked around and never been back (and it had been years since they did that). Another part had registered, posted 1-3 times, then never come back (including never logging back in). You also had your spam accounts or multiple accounts (people who forgot their login info and created another account). Etc.
In the end we found there were less than 300 regular members. We deleted all the accounts where they had never posted and it had been 2+ years since they created an account. That cleared out a huge amount of members. It also caused the software to run faster not having all that data in the system anymore.
Numbers don't really mean much. But it is still impressive non the less. Even if someone does not post, as long as they log in they are an active member. So ~400 people a day on the forum is still a **** of a lot of people.
