One of the most important things about a blog is to have comments so that you can engage with your audience and readers. Creating engagement in your articles/website is a great way to create community engagement from your readers.
For years I personally have been using the Disqus commenting platform and I love it, but with more and more social integration becoming the norm, it is good to consider other alternatives such as Google+ comments.
Google+ Comments is essentially the commenting system that you see in the Google+ social network and on YouTube. Any activity that happens on your blog or website in regards to comments from users will also appear on that users Google+ profiles and network.
For some people, they may think Google+ is a dead social network, for me I think it is like the gold fields of untapped gold. It is a great platform but still in its early stages of growth. Getting in now (2014) can put you and your website in a really good position, and one way to help that is to add Google+ comments to your website.