Infomercials are direct response television commercials which generally include a phone number or website. There are long-form infomercials, which are typically between 15 and 30 minutes in length, and short-form infomercials, which are typically 30 seconds to 120 seconds in length. Infomercials are also known as paid programming (or teleshopping in Europe). This phenomenon started in the United States where infomercials were typically shown overnight (usually 2:00 a.m. to 6:00 a.m.), outside of prime time commercial broadcasting peak hours. Some television stations chose to air infomercials as an alternative to the former practice of sign-off. By 2009, most US infomercial spending is during early morning, daytime, and evening hours. Stations in most countries around the world have instituted similar media structures. According to tapebeat.com, over $150 billion of consumer products in the US are sold through infomercials.

While the term "infomercial" was originally applied only to television advertising, it is now sometimes used to refer to any presentation (often on video) which presents a significant amount of information in an actual, or perceived, attempt to promote a point of view. When used this way, the term may be meant to carry an implication that the party making the communication is exaggerating truths or hiding important facts. Often, it is unclear whether the actual presentation fits this definition because the term is used in an attempt to discredit the presentation. Hence, political speeches may be derogatorily referred to as "infomercials" for a specific point of view.