SEO is a very broad topic. I think that comment marketing is an important part of it, but there are some other strategies which are more important. I am not sure, how it works effectively, but I guess there are some keywords that are used in order to make people buy what you're selling. It's a very interesting topic! I hope someone can give some tips!
Comment Marketing is an out of date marketing strategy for SEO. I would focus on your personal information being naturally shared. Google knows when you are using it to gain brand awareness and SEO tactics. If you are marketing on a forum make sure you are answering questions like this response and it will not be flagged. Better SEO tactics come from the following:
Keyword Research and then writing great quality on your website. (Content Marketing)Syndicate that content to sources that you partner with or obtain links by gaining partnerships. Make sure you use an ethical way of using SEO. Its all about fitting the customers wants.
Website Structure on your website goes a long way. Focus on Local SEO then tray your hand at ranging further and further away.