Google can't discount every type of link otherwise they would never be able to rank anything. All links count for somthing and forum sigs do help.
Forums sig helps you to get your website crawled faster especially when its new. I am not sure if it helps in SERPs but they are counted as backlinks in all major SE including Google as well.
I guess forums allow this kind of 'advertisement' because this way they get more willing members to post more posts which keep the forum alive.
For me Forum signature is a big help... especially on new sites. most of the time the spiders crawled the dp which also crawled your links and may increase your SERP and PR
I've seen some forums where the admin makes signature links NoFollow, so it won't help with search engines in those cases. Still, people see your link and if you are making quality posts, might visit, so its worth doing I guess. I use signatures, but only because I am already posting anyway. I wouldn't go off and make hundreds of forum accounts just for the backlinks.
you may try to check if Dp is being crawled. just type your username here in DP to Google search. try it. so i say it really helps to put your link on SERP.
I don't know if DP sigs will help your SERPS rankings, but overall having links on various community sites in your niche can help a lot. Just remember, a link is a link.
Oh yes, they definitely do help. You just need to use a tool like www.online-utility.org to see how signature links can really stack up. In my experience Google Groups is a good place to start. It gets lots of attention (funnily enough) from the Googlebot and you can be fairly confident that any link left on there will be in the SERPs within a few days. Search engines just love forum sites - the bots can hop from one page to the next crawling new content every day.
Show in the SERPs?? I would like to see one for a competitive search term...any evidence to back up the claim?? Also how do you know what value, if any, Google assigned to forum links??
All I can say is it certainly helped me - when I did a Google on my blog names some of the first results to come up were from my Google Groups signatures. Reading the replies above I'd say some people agree with this.
What you see happening is MustRank. If I type in any of my website URL's then I should be the #1 listing. If I type in Pepsi then Pepsi should be the number 1 website. In order for Google to be the most relevant search engine, when a brand name or url is typed into the search box, the website returned at #1 must be the branded website. Coke = coke.com McDonalds = McDonalds.com NFL = NFL.com aka MustRank
Those who have been doing SEO for a while will know that Google devalued signature file links in the famous Florida update in 2003. Where they have no value of very little no one is sure. I have still to see any respected seo say the signature file links have any real value in Google. People should take the hint that using signature files as link building is a total waste of time. Why would Google tread them as valued links? Any one can create them.
This thread was a great help. I have been looking to rent a few signatures and I just got a PM not more than 5 minutes ago wanting $60.00 for many thousands of signatures. Thanks for saving me some $.