Direct mail is a marketing technique in which the seller sends marketing messages directly to the buyer. Direct mail is a unique blend of advertising and sales. It is sometimes referred to as direct marketing or direct response marketing. Direct mail is, as the term implies, a marketing message that's delivered to prospects by mail. It is opened one piece at a time and read one piece at a time.

Direct mail is a way of advertising in which advertisers mail printed ads, letters or other solicitations to large groups of consumers. It is used in many different situations, limited primarily by the imagination of the advertiser. The term direct marketing is believed to have been first used in 1961 in a speech by Lester Wunderman, who pioneered direct marketing techniques with brands such as American Express and Columbia Records.

There are two main definitional characteristics which distinguish direct mail from other types of marketing or advertising. This involves commercial communication (direct mail, e-mail, tele-marketing) with consumers or businesses, usually unsolicited. This aspect of direct marketing involves an emphasis on traceable, measurable positive responses from consumers regardless of medium.

The most common form of direct marketing is direct mail sometimes called junk mail, used by advertisers who send paper mail to all postal customers in an area or to all customers on a list. While many marketers like this form of marketing, some direct marketing efforts using particular media have been criticized for generating unwanted solicitations. Some consumers are demanding an end to direct marketing for privacy and environmental reasons, which direct marketers, are able to provide by using "opt out" lists, variable printing and more targeted mailing lists.

Direct mail is one of the most measurable methods of marketing. It is attractive to many marketers, because in many cases its positive effect can be measured directly. Yet since the start of the Internet-age the challenge of Marketing Executives is tracking direct marketing responses and measuring results. Response rates are generally higher when the response device is separate from, rather than part of, the brochure or letter. Response rates to prospects (non-customers) average around 1%.

One of the most important parts of your direct mail piece is the response mechanism. For example, if a marketer sends out one million solicitations by mail, and ten thousand customers can be tracked as having responded to the promotion, the marketer can say with some confidence that the campaign led directly to the responses. By contrast, measurement of other media must often be indirect, since there is no direct response from a consumer. With direct mail marketing you can code your mail pieces to determine the exact number of responses you received from each campaign.

Direct mail is one of the most common forms of direct marketing in use today. Direct mail is a dynamic, versatile marketing tool and is the most heavily used direct marketing medium, and its popularity continues to grow despite postage increases.