An advertising or marketing technique in which promotional activities are carried out through less conventional methods than the customary channels of advertising to promote products, services, or ideas which commonly fall under the banner of above-the-line strategies. These may include channels such as direct mail, public relations and sales promotions for which a fee is agreed upon and charged up front. Below the line advertising typically involves direct means of communication, most commonly direct mail, e-mail, telephone, face-to-face promotions, often using highly targeted lists of names to warrant large response rates.

It is known for short as BTL.