Does anyone make money by advertising signature in forum. How about the income. how many money for one click.
I don't quite get what you mean here. Are you asking how much money you can make from having affiliate links in your signature of forums? If this is the case then the only person to answer this is yourself once you try it. No one can tell you how well it will really work for you. It depends on how many posts you have, how good your posts are, your forum reputation, the affiliate program you try and promote, etc.
If you are asking how much you can get paid for advertising someones site in your signature, answer would be: As much as some one is ready to pay. I saw some offers for 4-6$ per month and they had around 1000+ posts.
I've paid $40 for a monthly sig before on just over 5,000 post and it was not worth it in the end as I wanted it for the traffic and not for PR or backlink gain.