Disqus uses its own anti-spam software to smartly combat comment spam. It was designed to learn over time and becomes increasingly accurate with your moderation activity. Spammers are a prolific bunch, and thus there is always some chance that newer techniques may initially get past the anti-spam. These are tips on how to reduce or altogether eliminate spam.

Mark spam

Be sure to mark comments as spam if they are indeed spam. However, be careful not to mark non-spam comments, even if the comments are abusive, offensive, or just plain disagreeable. Marking non-spam comments as spam pollutes the data that Disqus collects and results in less accurate anti-spam detection.

You may mark comments as spam from the Moderation Panel, the comment thread itself, and from email notifications.

Pre-moderation

You may choose to pre-moderate all comments posted on your site. All comments, spam or not, will require moderator approval before being published for others to see. Another option you may want to try is pre-moderating all links in comments. To view and change moderation settings, head to Settings > Moderation.

Blacklists and Whitelists

Disqus offers both blacklists and whitelists. After marking comments as spam, you may add the commenter to your blacklist. Alternatively, you could require pre-moderation on all comments and then add trusted commenters to your whitelist.

Decide who is allowed to comment

By controlling who comments on your site, you can prevent spam or other undesirable comments from being posted on your site. You can view these options under Settings > General.

Akismet

Akismet is a popular anti-spam service. Disqus Comments supports Akismet as an additional anti-spam measure. To enable Akismet, enter your API key under Settings > General. Once enabled, Akismet anti-spam will be used in conjunction with Disqus anti-spam.

One technique by spammers is to create valid accounts with Disqus and leaving seemingly innocuous comments, but adding undesirable spam links. If you encounter such a user account, visit their Disqus Profile and click Report abuse or spam at the bottom of the page.