Blogging for two years now there is something I can tell my fellow bloggers they should never do:
Don’t ignore the people who comment on your blog.
What sets a blog out from an online magazine or newspaper is the interaction with the post author. If readers take the time to post a comment or ask a question, then you should take the time to respond to them. Not only does this incite the user to return to your blog to read the comment, but it also shows other readers that you engage in two way conversations with your fans.
A reader who visits an article where there are no responses to other comments is less likely to leave one themself. Your interaction helps also establish your online persona and gives you a voice that goes beyond what is written in your post.
Even if you are responding to negative feedback, do so tactfully and deliberately remembering that hundreds or thousands of others will be reading your replies. Remember this and use your comments to help reflect the way you want to be known and recognized. You can sometimes answer questions and direct users to other informative articles on your own site which can help retain users on your site for longer periods of time which help lower your bounce rate.
As a general rule of thumb, you should try to respond to comments as quickly as possible, take too long and the reader may have forgotten their own comment. I myself being a part time blogger often can’t respond to comments until hours after they are left.
One thing that is hard to know is if a user will even see your reply, by default do you have your blog setup to subscribe a user to comment replies? If not you may want to consider it. Don’t default them to getting emails when anyone comments, only if a direct reply is made to theirs or the will get email spam from your site.
I myself visit other blogs often and like when I get an email notice with a reply to my own comment but dislike when I get emails from every comment on the post. Some blogs can only sign you up for all comments and not just for replies only. I also very much dislike the way blogger.com handles replies and the whole system should be revamped to integrate Disqus or something in my opinion. Most blogger blogs are setup to pop comments in a separate window which only slows down the comment leaving process.
Take comments seriously and remember that each reply you provide is your voice and use that voice wisely. Make it as easy as possible for people to leave comments on your blog and get updated when you respond to their comments.