Okay, this may be obvious to some people, but I still find this problem on so many blogs, and both of these are easy fixes.
1) Your comments aren't social.
You don't respond to comments and the comments system gives no way to respond to comments or subscribe to them. This is a huge failure in my eyes. What's the point of commenting or even coming back to your blog if I can't subscribe or reply to comments?
Guess what? The days of “commenting and running” are over, and your blog is a place to have a conversation. If you just want to present material and not have a conversation about it, don't bother opening comments at all (in fact, lots of people close down comments on particular blog posts because it will spark TOO MUCH conversation, which is the other extreme of what you want).
For this reason alone, I do not advise people who are starting blogs to use Blogspot. God, I hate the Google commenting system. Sure you can reply to people, but the original poster will never know they've received a reply! There are no notifications!
WordPress has far better options for social commenting, and you can even choose a third-party system like Disqus, like I did. This way the conversation keeps going! Your commenters will return regularly for your insight and the insight of other people who read your blog. Changing to a social commenting system is the biggest boost you can make for your blog.
2) You have no sharing buttons.
The same blog I went to two weeks ago that didn't have social comments, also did not have social sharing buttons. So even though I loved the article and commented on it, knowing my comment would just sit there, I couldn't share the blog post to other people I thought would love it too. This is a HUGE mistake. If you wonder, “Why doesn't my blog get any traffic?” it's because no one is sharing your content. You give them no reason to because you don't provide readers an easy way to click-and-share.
Blogspot does provide a way for sharing to be added to templates and there are dozens of plugins on WordPress to add sharing to your website. I like SumoMe's plugin the best. It's free and comes with sharing plus ways to grab newsletter subscribers, etc. I've been very pleased with it so far.
Does your blog have these issues? They are both easy fixes and will hopefully increase traffic and interaction on your website.