nofollow links are not completely useless, because it existence is itself in doubt as how search engine use them, for blog commenting try commenting on blog that are high authority links, if its from high authority links with pagerank then it does not matter if its a nofollow or dofollow
for me, blog commenting is a matter. It is been a useful to me before but only you should comment to related site of yours.
When it comes to SEO, blog commenting is important. Not only can you contribute your opinions, show off your expertise, and get to know a massive amount of people in your industry – you can also build up valuable backlinks to your website that will increase its page rank.
Seems no one from here can answer to your question, so i will try. I think allowing blog commenting on your blogs is good, because sometime they can increase the keywords density if the comments are relevant to the post. If you allow do-follow you will loose PR (if you have) on internal pages where comments are enabled because you transfer PR juice to people sites that commented (this apply only if you have a lot of comments on that PR internal page). But PR doesn't influence SERPs, or at least very less, so leaving people to comment and express their ideas about the article is good, this way you can animate the place and gather some people around your blog, like a community. To manage your comments you should use some anti spam plugin such as akismet and another one for captcha, but the most important is to accept only relevant comments and not crappy ones. This is my opinion and how i see things from my personal experience. Hope this will help you somewhow.
Don't like spammy commenting on non topic relevant blogs, but find out it's usefull to comment topic relevant spots even if they are nofollow, just because of direct traffic. However, no impact on search engine results.
Blog comments has many advantages, and SEO is one of them Some of the benefits 1. Back links to your site - Which helps in SEO 2. Visitors to your site, an avenue of traffic source 3. Build your awareness and creditability, especially when you're new to the business
Dofollow blog commenting services provide SEO benefits. Along with providing immediate search engine ranking benefits like dropping comments on the dofollow blog, it also provides a lot of long term benefits wherein it enables you to leave thought provoking comments and help you connect with the millions of bloggers and enable to build your links directly. Indeed it is a great link building strategy.
Commenting on blogs is a good traffic generation strategy, depending on the traffic the blog gets, you may find a good one that gets you a lot of traffic.
Well they do so because alot of blog commenting software spam their wordpress software. You can suggest them to go no-follow or use captcha to be saved from spamming.
In SEO both Dofollow and Nofollow links play important role, but they should be from relevant source! Nofollow links important for drive traffic! Thanks.