I have a question. Are forums do follow. I mean that if post my signature or one of mine blog post on forums, will the backlinks be counted as authority backlinks?
That all depends on the forum. Some forums are nofollow while most by default do follow. Best way to find out is to simply view the source code of the page.
An easy way to tell is whether other people's signatures are mostly links or not. If it's all links, then you can be fairly certain that it is do follow. If in doubt, view the source and do a search for 'nofollow'.
you can simply use a seo tool to check if a certain forums or blogs has a do follow or no follow link. There is a tool that that highlights no follow link.
Incidentally, there is still much debate over whether 'no follow' links are really as worthless as popularly believed. -Vish (Zephyr Writing).
NoFollow is to block the PR bleed on a Google link. But it has no affect on Yahoo or MSN. They don't have PR. With that said, will the SEs follow that link during indexing? No. Therefore, where is the value?
Aren't websites meant to be for humans as well as machines? A no follow link won't be indexed but human eyes will see your domain and may be curious. So you'll still probably get more visitors using forums with no follow links. That's the value. Get your domain name out there!
It depends on the forum. You can use search status adds on to see if the forum you're posting with are dofollow or not.
currently most of forums are dofollow, you will get back link for sure. It's upto forums/websites which links are going to be counted as authority links.