I noticed there are 564 guests online and 37 users. Why so many guests? Are guests people who are not members and are just looking at the forum?
IIRC Guests are people not logged in, they might be a member but not necessarily.
I assume they are looking for some piece of code / library grab it and continue their project.
Imho this amount indicates that the Arduino ecosystem is larger than on first sight.
I'm member of a few sites, but I probably visit a few hundred sites as guest every week. I guess a lot of people do.
Great! 
I'm sure there's a few human guests, but mostly they're web robots: search engines, probably a few scans looking for security holes, things like that. You'd be amazed at the amount of that type of traffic on a web site.