Penalty: In search engine optimization, a penalty is a ban or demotion in page rank on a search engine due to spamming practices. These penalties may be applied to websites either manually or automatically based on algorithms.

In order to provide high-quality results to searchers, search engines develop algorithms to recognize common strategies and characteristics of spam sites. These “black-hat SEO” strategies including link building through illegitimate methods (such as by paying people to embed links to your site through the web) or comment spam. More recently, experts have speculated that too much guest blogging can be viewed as spam as well.

Google does not publish the algorithms it uses to determine rankings in order to prevent exploitation, but it has been common knowledge since the Penguin update in 2012 that bad linking practices can result in penalties. Google does, however, provide “webmaster” guidelines that outline quality expectations.

There are several strategies legitimate sites can use to avoid an SEO penalty if they accidentally exhibit these characteristics. Site administrators should run regular link audits to make sure any links leading into the site are from other reputable sites, and ask that links be removed from low-quality sites. Sites should also make sure their keyword densities are not too high so as to trigger alerts.