Google sent 45 million notifications to registered website owners through Search Console in 2017, and of those, 6 million were related to search spam. Guidelines and details on how to fix the problems were included along with the emails.
The 45 million notifications alerted the website owners to possible problems with their sites that could affect the appearance of content in search results. Not all were related to search spam.
Google's algorithms can detect the majority of spam and demote the content in search results, but also rely heavily on human reviewers to manually review pages and flag them if they violate the guidelines. It's a little surprising that with all its expertise in technology, it still relies on humans to make a call. Google will either flag the site, demote it, or even remove it entirely from Google search results.
The Manual Actions page lists known issues on a specific website and provides information to help those that own the site address the problem.
Google holds numerous patents to detect spam. Microsoft does, too.
Microsoft was granted a patent in 2016 to detect search spam that includes “a self-monitoring subsystem to uncover spam patterns and a self-protection subsystem to protect against spam by providing spam-related information to strengthen a relevance ranking algorithm.” It searches, scans and analyzes URLs based, in part, on one or more spammer targeted keywords.
Just as important is a method for characterizing context-sensitive search results as non-spam -- for example, one patent from Northwestern University.
For those who need a refresher because they have too much information to keep track of or a definition has slipped their mind, Google refers to “spammy” search results as a site trying to “fool or manipulate” its ranking system.
Some spammy pages try to trick searchers into providing their personal or financial information or subscribing to a service with unclear terms, wrote Juan Felipe Rincon, global search outreach lead at Google.
Similar to the way Google flights email spam in Gmail, the search platform works to keep query results clean. Overall, the company in 2017 said it detected and removed more than 80% of hacked sites from its search results.