We all do blog and forum comment and place links in signature but we know that link exchange is very useful for getting top 10 ranking in search engine result page. Is forum also useful for getting top 10 ranking? I think we can not compare forum links with link building. What is your experience for both seo activities?
Honestly, both are GREAT for your website, but I believe links coming to your site from larger sites that have a lot of traffic going through are the beat things to have in terms of getting your site ranked and getting traffic.