Digital multicast television network

A digital multicast television network, also known as a diginet or multichannel, is a type of national television service designed to be broadcast terrestrially as a supplementary service to other stations on their digital subchannels. Made possible by the conversion from analog to digital television broadcasting, which left room for additional services to be broadcast from an individual transmitter, regional and national broadcasters alike have introduced such channels since the 2000s. By March 2022, 54 such services existed in the United States.

Typically run on a lesser budget, national multicast services often rely on archive and imported content and are tailored to allow advertisers to reach specific demographics. Most of their revenue is derived from national advertising.

The first multichannel broadcast in Australia was ABC Kids, which broadcast from 2001 to 2003; in the succeeding years, the country's commercial broadcasters also launched secondary services to compete against DVDs and online piracy. However, their ability to do so was hampered at first by a ban on adding channels, with a focus on such services as datacasting and high-definition. It was not until 2009 that commercial broadcasters were allowed to add multichannels; in that year, the three major networks all did so, bringing the number of channels they offered from three to eleven.

The original commercial multichannels were generalist in nature, which made it difficult for advertisers to target specific demographics and therefore made them less lucrative. The shift to specifically targeted services and their reliance on existing programming has allowed these channels to survive despite drawing comparatively low shares of the audience: in 2018, 7mate led the group with an audience share of 4.1 percent among metropolitan audiences. However, after the Australian Communications and Media Authority permitted the commercial broadcasters to move required children's programming and national drama commitments to their multichannels, ratings and visibility fell precipitously; by 2013, the ABC had more viewers for its children's channels than the commercial broadcasters combined. The commercial broadcasters also became more reliant on news, sport, and reality competitions on their main channels.

Each of the five major broadcasters offers its own suite of multichannels:

In 2017, TV Azteca launched a+ (now A Más), initially conceived as a hybrid regional-national service to be carried on its existing Azteca 7 transmitters in most of Mexico. The new channel—as well as news channel adn40, aired on Azteca Uno transmitters, achieved sufficient national coverage to be classified a national network by the Federal Telecommunications Institute in December 2017, making it mandatory for satellite TV providers to add it to their lineups.

For most of the 2000s decade, digital multicasting in the United States remained less used. One of the earliest successful uses of subchannels was to broadcast automated weather information. The first such subchannel was the 69 News Weather Channel, launched in February 2001 by WFMZ-TV in Allentown, Pennsylvania, with the assistance of AccuWeather. In 2004, NBC and its affiliates launched NBC Weather Plus, which was available in its peak from more than 80 stations nationally. Another early subchannel user was The Tube Music Network, which broadcast music videos from 2005 to 2007 until closing for financial reasons.

2008 was a critical year in the shift toward programmed digital multicast services. NBC Weather Plus was shut down at the end of 2008 in a decision taken by the network's affiliates. Several new channels offering classic TV programming were launching or growing at the time. These included the Retro Television Network (RTN), started in 2005 by Equity Media Holdings as the first such service, and This TV, a film-aimed service run as a joint venture between Weigel Broadcasting and film studio MGM (now owned by Amazon). Another planned subchannel of this type, the .2 Network, was announced and signed up affiliates but never launched amid the Great Recession. These subchannels offered stations the ability to expand their advertising inventory and offer lower prices on the secondary services. In addition to services signing up national affiliates, some station groups were starting to experiment around this time. CBS explored, but never launched, a complementary secondary channel, dubbed "CBS 2". In 2007, Ion Media, which owned a network of transmitters serving most major American markets, launched its 24-hour kids channel Qubo (owned by Canada-based Corus and NBCUniversal, closed in late February 2021) and health and wellness service Ion Life. Weigel launched MeTV, which had formerly only been a local service in Chicago and Milwaukee, on a national basis in December 2010; four years later, it was the most widely distributed multicast network. It remains the most-watched; in 2021, it had an average prime time audience of 752,000, nearly double the next-highest diginet and greater than cable channels such as Bravo, Lifetime, and A&E.