Blog spam is unsolicited messages or comments that appear within blogs. Their goal is to disseminate links for advertising purposes. Spam entries on blogs are usually triggered by software, so-called bots, in order to leave behind as many entries as possible on different blogs within a short period of time. The links contained in the blog spam entries are intended to increase the link popularity of the web page to which they are referring. It is technically only possible to disseminate blog spam if the operator permits entries or comments without approval.
Be wary of search engine optimization providers working with blog spam. Blog spam can have a lasting negative impact on the ranking of a web page, because these methods are detected by search engines.