As simple as it might sound, this is often overlooked. You can ask for comments in your writing, but your “comment links” also speak volumes. Does your comment link say “22 comments” or “22 people commented, what’s your opinion?” And if you tested it, which one do you think would attract the most comments?

You don’t have to respond to “wow, cool post”, of course, but if someone has a decent remark, it’s only fair to respond to it and see if you can do anything with it. This will encourage other readers to post their comments too. If someone has really added value to your post, the best thing you can do is do a small update to your post, and give the commenter kudos for his good remark, or maybe even a link.