Signature links are great, even if they don't provide you much juice(I guess, no one knows for sure how much juice) but they are the best way of promoting your links to the real people and most of the time, they are related traffic as well, when you post in related forums. For high ranking, one can try web directories, post reviews, and link exchanges etc.
I think there are because of many unrelated links in one page of forum, so google not counted those links much.
I agree that forum sig links may not count much when it comes to google but I do get 'real' people looking at my signature and visiting my site. So they act as direct referrer. Of course if your sig is in some niche forum it would should count for google too.
I'd like some opinions - do you join in the conversation on forums and really become part of the community or just superficially participate in many forums? Would becoming part of the community in a few forums be equally as effective from a backlink point of view?
I seen to remember a way to tell when my SBI site has been crawled. Is there a way within SBI or do I have to look else where.
I agree with jitendraag although the signature links don't count for much juice they actual attract real people and bring in a couple more people