Self-hosted WordPress sites often attract a lot of comment spam which requires your valuable time or resources to reduce to more manageable levels.

• We recommend automatically turning off commenting on older posts, because these are the posts that often rank very well in Google which attracts the spammers in the first place. Most blogs choose to turn commenting off on posts that are three months old or older. (We usually do six months.)By turning off commenting on older posts, our spam dropped approximately 25% and it didn’t cause our WordPress site to load any slower.
• Akismetis possibly the most effective method of reducing spam through a WordPress Plugin. Akismet works by connecting to a hosted web service to determine if comments or pingbacks are spam or legitimate.By using Akismet, we reduced the amount of comment spam by nearly 100%, but Akismet unfortunately isn’t free any more for business users.
• Disqus is an amazing WordPress Plugin that is used for commenting. Disqus uses a hosted web service to moderate comments and automatically connects to an extensive blacklist and whitelist to reduce the amount of spam comments automatically.
• Bad Behavior is one other WordPress plugin we use to reduce spam by not allowing the spammers to access our site in the first place. Bad Behavior works by analyzing the way the browser/program/user is using the blog and blocking them, and of course Bad Behavior also has an extensive database of common spammer Ip addresses that it also uses to block.

What is your preferred method for reducing comment spam? We believe that there’s no one technique that will completely eliminate spam, but these techniques together will help you better use your resources.