Do you feel it is worth the time to comment on as many forums and blogs related to your forum category to get some traffic from blogs and forums?
I think it can be worth it if your forum has good content for new visitors to read, but posting on other people sites can also be kind of time consuming, and the time can be better spent on improving or adding more unique content on my own forum if my forum does not have a lot of posts.
I prefer using SEO, writing unique and informative content which search engines will more likely index, improving the community, so more people might want to join, and link exchanges.
Plus, using Youtube, Twitter, Facebook, and other social networks.
It's always worth it to get your link out there as long as it is done respectfully of the site you are commenting on. I know I had to censor out two URLs spammed today on people's profiles on my forum, so it pays to read the rules first =) But if people do so according to the site's allowances on links then I got no issue with it.
Yes, if it's done properly on an active website, it will definitely provide you will good traffic. Also, a good optimized link on an active and PageRanked blog may get you a good SERPs ranking, which in turn gets you good traffic.
For blogs I recommend using All-In-One-SEO and for all types of sites/blogs, I recommend making a sitemap. That helps with the search engine rankings.
I use Yahoo Answers as a way of helping to promote my blog links. When I see a question that I have a post relates to, I answer the question and then I link the user to the specific blog post in the sources area after answering the question.
This may only get one visit, but Yahoo Answers should have high rankings, so if your links sit on such a site, should help build rankings too.
I've also taken to twitter, and I've used Twitterfeed to have it automatically "tweet" my blog posts on twitter. Since doing that, I've had 3 visits from twitter so it does help a little.
