Links from the internal pages of forums are heavily discounted by the major search engines. For ranking purposes link quality is an important factor and a few high quality inbound links are worth more than hundreds of signature links.
Somehow my so-called web site has managed to stay near the top for "randall blank
" in Google. It's even been known to grab the #1 spot from time to time -- as it is right now at MSN
-- but as far as I know there's only one
link to it outside these forums. And it's not even in my sig, though I do wonder if my archived email at Gmail has anything to do with it. I don't link to the site (why would I?), but the domain name is there.
Postings like this one may give me a boost for a while, but it's still self-referential gobbledygook.
On the other hand, Google only shows 573 hits (even less at MSN), so the competition isn't all that fierce...