I think its easy to think of your own forums as being big or well known because they reside within their own niche but when it comes to forums in general, your own site may be much smaller. In general, when do you consider a forum to be big or big enough? Does it really matter if you are joining a small community or a big one?

When my forum reaches its 500th member (halfway there now), I think I will consider it to be big.

Then again, at that point, 1000 will 'be big'...and so on and so on.

Personally, I see hobby sites as being big when they have over 500 members, but large corporations/established sites need to have bigger numbers.

eg: if vb.com had only 1000 members, I would consider it to be less than big.

*rambles*

Well, I am not sure what is considered big. I'd say from 1000 members upwards and at least 20+ new threads per day.

With a little over 13,000 registered members (around 8,000 active members) I'd say I run a big forum. I'd say big because we have only been around for less than three years and our forum is an unofficial fan forum for Pearl Jam who are not all that *popular* these days as they're not exactly a mainstream band and have zero media presence. Big because we prune our forums quite often and still have around 150,000 posts with around 200-300 average new posts per day.

I would call a forum "big" depending on what the forum is mainly about. If it was about some little thing or so, probably 250+ with frequent posters I would say would be big. If it was some forum about an operating system like OS X or XP, 10,000 I'd say would be a bit big.

A forum I would say is quite big for its subject would be WebHostingTalk running vB2.

It is big if your members return on a regular basis :)