The roots of spam, which is the use of electronic systems to send unsolicited, bulk messages, can be traced back to the mid 1990s, when the internet first started to become affordable to the general public.

Beginning with email, spam rapidly spread to new technologies, such as instant messaging, newsgroups and mobile phones. As social networks such as MySpace, Facebook and Twitter became increasingly popular, spam quickly found a new home.

Numbers are on the rise, too. Last year, the estimated figure for total spam messages sent  across all technologies was seven trillion. But what is social media spam, and how can you spot it?

This infographic from Seo Smarty provides a handy one-page resource as to how each of the major social networks defines spam, what sort of spam you can expect and their position therein.

(Source: SEO Smarty.)