Yes, I'm sure people do visit and revisit threads all the time, depending upon their level of interest (or boredom) of course :lol:
But it seems to me that when the number of hits reaches 500-1,500 we are talking about a rather significant number of fist-time readers, especially when the number of posts per thread is in the range of just 6-12. Regulars do tend to keep track of dates and times, skipping threads that they have already read, for example. Also, the system is designed to keep active threads at the top so readers know what to look at when they are looking for new info.
But really, I'm only speculating here. What seems very clear is this forum (The Teen Help Industry) is second to none of it's kind that I know of on the Internet. Just how BIG it is, only Ginger can say.