The term "junk mail" refers to unsolicited bulk mail that is often sent in large quantities by companies, organizations or individuals for advertising purposes. It is also known as direct marketing materials and can include catalogs, flyers, postcards, coupons, promotional offers, etc., which are usually not of interest to the recipient and are typically thrown away without being read. The term "junk mail" is often used pejoratively because it is seen as a nuisance and waste of resources, both in terms of paper usage and postal services.