How does Google see dofollow links in signatures from forums that require registration to view them ? I try searching for a few post URLs on Google to see if they're indexed and they're not. Are these links useless then ?
They certainly will not help SERP if the SE can't see them... If guests can not see the link, then bots can not, it's often as simple as that, though some forums/sites do allow the bots in, but I think that is rare. They can help for traffic though, assuming the forum has a good member base, so they are not completely worthless.
It would probably be smart for a forum owner to let bots in even if they don't let guests in. It would cause their site to get indexed, but when people come looking for the thread they would have to see it. Of course, most forum owners don't do that. As a rule of thumb, if guests can't see the link, then search engines can't see the link. Thanks, Scott