Yeah, forum posting can get you good amount of traffic towards your website. But while posting on forums you need to be much more careful and should read their terms and conditions first else your account will be banned for ever.
Please, give some proofs for this point of view, as we have not witnessed any significant increase in traffic due to forum posting.
that depends on how reputable your profile on a particular. Say for example you have 10 newbie profiles - that basically wont do you any good.
That's why you should put some hard work into these profiles - to have 10 reputable profiles on 10 different forums - that would definitely do good for you. Yet it will not attract any customers directly, IMHO.