N. Amer. plural noun: infomercial
1. an advertising film which promotes a product in an informative and supposedly objective style.
An infomercial is a form of television commercial, which generally includes a phone number or website. There are long-form infomercials, which are typically between 15 and (more commonly) 30 minutes in length, and short-form infomercials, which are typically 30 to 120 seconds in length.
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.