The term spam refers to unsolicited messages sent in indiscriminately and in bulk. Spam is usually sent through email, but can also appear in forums, blog comments, and on social media.

Spammers send these messages in the hopes of getting people to sign up for services, buy their products, install malware without the knowledge of the recipient, and even scam people.

While there may be reputable businesses that send spam, the negative rap that goes with it means that those using spam as a marketing technique can hope to have very low conversion rates. Despite low conversion rates marketers still persist in using this method due to the low cost associated with spamming.

Email spam is the most common form of spam, hence spam or junk folders in emails nowadays. Thanks to the more advance filtering systems, most spam emails are caught early on and automatically sent to the junk mail folder, thus lessening the clutter in people’s inbox.

The problem with these filters though is that it can result in false positives, which means that valid email sometimes get sent to the junk mail folder. Furthermore, as email providers grow more advanced so do the methods that spammers use, which is why spam email still manage to pass filters on a daily basis.

Aside from email spam, some of the media targeted by spammers include instant messaging, forums, blogs (especially the comments), guest books, wikis, file sharing and video sharing sites, and even search engines. Spam also exists outside the cyberspace, with businesses sending unsolicited messages through junk mail, as well as by calling on the telephone or sending text messages.