Editing Referrer spam

{{short description|Kind of spamming aimed at search engines}}
[[File:Referrer_spam_in_Webalizer.png | thumb | right | This is an excerpt of a screenshot of Referrer spam in the output of the Webalizer website analytics software.]]
'''Referrer spam''' (also known as '''referral spam''', '''log spam''' or '''referrer bombing''') is a kind of [[spamdexing]] ([[spamming]] aimed at [[search engine]]s). The technique involves making repeated [[web site]] requests using a fake [[HTTP referer|referrer]] [[URL]] to the site the spammer wishes to advertise.<ref name="TheGuardian2005">{{Cite web |url=http://www.theguardian.com/technology/2005/aug/25/onlinesupplement |title=Moral maze |date=2005-08-24 |access-date=2022-10-06 |website=[[The Guardian]] |last=Pollitt |first=Michael |archive-url=https://web.archive.org/web/20140919102702/http://www.theguardian.com/technology/2005/aug/25/onlinesupplement |archive-date=2014-09-19 |url-status=live |language=en}}</ref> Sites that publish their access logs, including referrer [[statistic]]s, will then inadvertently link back to the spammer's site. These links will be [[Web indexing|indexed]] by [[Search engine|search engines]] as they crawl the access logs, improving the spammer's [[PageRank|search engine ranking]].<ref name=":0">{{Cite web |title=Referral spam: attack patterns and countermeasures |url=https://www.ionos.com/digitalguide/online-marketing/web-analytics/referral-spam-causes-and-countermeasures/ |access-date=2023-05-14 |website=IONOS Digital Guide |language=en-US}}</ref>

At least since 2014, a new variation of this form of spam occurs on [[Google Analytics]]. Spammers send fake visits to Google Analytics, often without ever accessing the affected site. The technique is used to have the spammers' URLs appear in the site statistics, inducing the site owner to visit the spam URLs. If the spammer has never visited the affected site, the fake visits are also called '''ghost spam'''.<ref name=":0" />

== Mitigations ==
Techniques for mitigating referrer spam include blocking spam [[Web crawler|crawlers]] and filtering out known spam domains in analytics software.<ref>{{Cite web |date=2022-08-28 |title=How to Block WordPress Referrer Spam in Google Analytics |url=https://www.wpbeginner.com/wp-tutorials/how-to-block-wordpress-referrer-spam-in-google-analytics/ |access-date=2023-05-14 |website=www.wpbeginner.com |language=en-US}}</ref> The open-source analytics company [[Matomo (software)|Matomo]] maintains a [[public domain]] [[Crowdsourcing|crowdsourced]] list of spam-associated domains which it uses in automatic filters.<ref>{{Cite web |last=Team |first=Matomo Core |date=2015-05-13 |title=Stopping Referrer Spam |url=https://matomo.org/blog/2015/05/stopping-referrer-spam/ |access-date=2023-05-14 |website=Analytics Platform - Matomo |language=en}}</ref>

==See also==
* {{annotated link|Adversarial information retrieval}}
* {{annotated link|Spam in blogs}}
* {{annotated link|Referer spoofing}}

==Notes==
{{reflist}}
==External links==
* [https://github.com/matomo-org/referrer-spam-blacklist Referrer Spam Blacklist] by Matomo – a public domain crowdsourced list of referrer spammers containing over 2250 domains as of May 2023.
{{Spamming}}

{{DEFAULTSORT:Referrer Spam}}
[[Category:Black hat search engine optimization]]