Selected answers from the Dumb SEO Questions Facebook & G+ community.
David Kutcher: No, and even if they did, don't be that person.
Mark Sass: I'm not talking about spamming, but rather if all the comments I made have any effect.
Arseniy Bolotsko: No benefit and if added rapidly could be harmful.
Yassine Aïssaoui: Make great content on your blog (dofollow or nofollow).
Ian Dixon: Making comments may not bring much in SEO terms but people see the link and click on it. I only comment when I have something to say. If the site blocks me from putting in a link to my site then they can go away. I do them a favour by adding a comment to their site so they can at least return that by having my comment linked to my site.
Roderic Van Binst: From an SEO/ranking perspective no, you won't benefit from no follow links from a blog post. ;
Blog commenting can however be used a tactic, bringing several benefits. Instead of explaining them here, check out:
Chris Shaffer: +Roderic Van Binst ;I disagree, NoFollow links CAN have immense SEO value (Think wikipedia) While they may not pass PR the have an impact on traffic and are part of a natural backlink profile. Now +Mark Sass ;comment links are not particularly valuable, but that doesn't mean they have NO value. That being said, don't comment just to get the link +Roderic Van Binst ;'s video is a great place to start to learn about the real reasons for and impact that comment marketing can have. The trick, as with any seo, is to add value. ;
Ranu Jain: I completely agree with +Chris Shaffer.
Dofollow links helps in boosting up your website's search engine rankings. But yes, the links should be from relevant sites. ;
In addition to this, search engines prefer a mixture of both types of links with a "natural" link profile. ;
Do no follow links to my website from commenting on other peoples blogs (the same topic) help my SEO? 
