Spamvertising is the practice of sending E-mail spam, advertising a website. The word is a portmanteau of the words "spam" and "advertising".
It also refers to vandalizing blogs, online forums or wikis with hyperlinks in order to get a higher search engine ranking for the vandal's website. Spamvertisers insert links to their websites (typically, sites purporting to sell some commercial product) and add keywords of common or related searches. The apparent goal is that a search engine will find the vandalized page full of links and improve the popularity rating of the pages to which they link. This is typically done by automated editing programs which look for editable text fields in web forms and automatically fill them in with web links. The links typically lead to pills, porn and poker sites.
Most legitimate website providers do not tolerate this practice, and will delete any site that has been spamvertised.
This practice has led to many editable online resources employing anti-spam countermeasures, including the use of captchas to prevent automated editing.
If you've received this notification from the Abuse Department via SpamCop, you'll be provided with information stating which website was spamvertised as well as a link to update/resolve the case with SpamCop. You'll need to ensure that you've visited the provided SpamCop link and selected the appropriate option for your case as well, ensure that your link is no longer spamvertised if applicable.