Of the legitimate guests, a lot are probably just folks researching C&V bikes and clicking links from Google of descriptions or pictures of components, frames, or bikes that they're researching. There's also a bit of a time lag so even if someone comes in for a few seconds to look at a picture it'll probably show them online for a few minutes, so that accumulates rather quickly.
In other words, they are present but not actually browsing the forum, per se.
-Gregory