A commercial advertisement on television (usually abbreviated to TV commercial, ad, ad-film, and known in UK as advert, or TV advert) is a span of television programming produced and paid for by an organization, which conveys a message, typically to market a product or service. Advertising revenue provides a significant portion of the funding for most privately owned television networks. The vast majority of television advertisements today consist of brief advertising spots, ranging in length from a few seconds to several minutes (as well as program-length infomercials). Advertisements of this sort have been used to promote a wide variety of goods, services and ideas since the dawn of television.The effects of television advertising upon the viewing public (and the effects of mass media in general) have been the subject of philosophical discourse by such luminaries as Marshall McLuhan. The viewership of television programming, as measured by companies such as Nielsen Media Research, is often used as a metric for television advertisement placement, and consequently, for the rates charged to advertisers to air within a given network, television program, or time of day (called a "daypart").In many countries, including the United States, television campaign advertisements are considered indispensable for a political campaign. In other countries, such as France, political advertising on television is heavily restricted, while some countries, such as Norway, completely ban political ads.The first official, paid television advertisement was broadcast in the United States on July 1, 1941 over New York station WNBT (now WNBC) before a baseball game between the Brooklyn Dodgers and Philadelphia Phillies. The announcement for Bulova watches, for which the company paid anywhere from $4.00 to $9.00 (reports vary), displayed a WNBT test pattern modified to look like a clock with the hands showing the time. The Bulova logo, with the phrase "Bulova Watch Time", was shown in the lower right-hand quadrant of the test pattern while the second hand swept around the dial for one minute.The first TV ad broadcast in Asia was on Nippon Television in Tokyo on August 28, 1953, advertising Seikosha (now Seiko), which also displayed a clock with the current time. The first TV ad broadcast in the UK was on ITV on 22 September 1955, advertising Gibbs SR toothpaste.Until the early 1990s, advertising on television had only been affordable for large companies willing to make a significant investment, but the advent of desktop video allowed many small and local businesses to produce television ads for airing on local cable TV services.