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.

David Michael Letterman (born April 12, 1947) is an American television host and comedian. He hosts the late night television talk show, Late Show with David Letterman, broadcast on CBS. Letterman has been a fixture on late night television since the 1982 debut of Late Night with David Letterman on NBC. Letterman recently surpassed friend and mentor Johnny Carson for having the longest late-night hosting career in the United States of America.

Letterman is also a television and film producer. His company Worldwide Pants produces his show as well as its network follow-up The Late Late Show with Craig Ferguson. Worldwide Pants has also produced several prime-time comedies, the most successful of which was Everybody Loves Raymond, currently in syndication.

In 1996, David Letterman was ranked #45 on TV Guide's 50 Greatest TV Stars of All Time.

Letterman was born in Indianapolis, Indiana. His father, Harry Joseph Letterman (April 1915 – February 1973), was a florist of British descent; his mother Dorothy Letterman (née Hofert, now Dorothy Mengering), a Presbyterian church secretary of German descent, is an occasional figure on the show, usually at holidays and birthdays.