What about links from signatures in forum posts? Do these have any value as links in Mr Google's eyes?
of course.. I usually put my new sites on my sig and in just a matter of hours I get index right away with big G.
I agree with bigcat. It may not make a huge dent in a highly competitive keyword, but can really help with the targeted ones.
It is valuable, especially with a lost of links from lots of posts! But you should employ many forums for best results...
I think too many people just comment in Forums to get a link, the links wont rocket you to page one so they should just be what they were intended and thats a small reward for contributing genuine helpful or topical content to an online community.
I wouldn't rely on just forum posts it's not enough you need variety in your backlinks to make it look natural
I believe those signatures are worthless specially when are unrelated to the forum topic. Related forums to the anchor text may help. Better place the link in the post. They carry value there.
I can't say for sure, but last October when I started doing forum sig links for my site I saw it rise in the search engine, slowly but surely. It could have been other factors too though.
There has lot of complications regarding it. What I feels, that these backlinks have no SEO values since many of them are no-follows but if we can post in well moderated and relevant quality forums, it will get genuine traffic from it.