Junk mail refers to advertising circulars, free trial CDs and other merchandising come-ons delivered by post to homes and businesses. The term comes from the fact that most of it usually ends up in the trash. Advertisers often call it "targeted mailing", as mail is usually sent out due to database readings. For example a person who likes golf may get junk mail for golf related products.

Some people like getting this kind of stuff and respond by purchasing the goods and services offered. Many dislike or resent it, and some jurisdictions like the US have laws requiring junk mailers to withhold their offerings from residents who opt out.

A stereotype commonly associated with junk mail is the misspelling of the person's name to whom it is addressed. A famous example from the television series Friends is a letter that was meant for Chandler Bing but was actually addressed to 'Ms Chnadler Bong'.

An organization called the Mailing Preference Service allows you to register with them for free and they will ensure your address is removed from 95% of mailing lists.

Mailing Preference Service (http://www.mpsonline.org.uk/mpsr/)

Junk e-mail is also known as spam.