Substack is an American online platform that provides publishing, payment, analytics, and design infrastructure to support subscription newsletters. It allows writers to send digital newsletters directly to subscribers. Founded in 2017, Substack is headquartered in San Francisco. History Substack was founded in 2017 by Chris Best, the co-founder of Kik Messenger; Jairaj Sethi, a developer; and Hamish McKenzie, a former PandoDaily tech reporter. Best and McKenzie describe Ben Thompson's Stratechery, a subscription-based tech and media newsletter, as a major inspiration for their platform. Christopher Best operates as chief executive as of March 2019. Content Substack users range from journalists to experts to large media sites. Among the high-profile writers to have used the platform are Pulitzer-Prize-winning journalist and author Glenn Greenwald and Seymour Hersh, culture critic Anne Helen Petersen, music essayist Robert Christgau, and food writer Alison Roman. The New York Times columnist Mike Isaac argued in 2019 that some of these companies see newsletters as a more stable means to maintain readers through a more direct connection with writers. In 2020, The New Republic said there was an absence of local news newsletters, especially in contrast to the large number of national-level political newsletters. As of late 2020, large numbers of journalists and reporters were coming to the platform, driven in part by the long-term decline in traditional media (there were half as many newsroom jobs in 2019 as in 2004). Around that time, The New Yorker said that while "Substack has advertised itself as a friendly home for journalism, [...] few of its newsletters publish original reporting; the majority offer personal writing, opinion pieces, research, and analysis." It described Substack's content moderation policy as "lightweight," with rules against "harassment, threats, spam, pornography, and calls for violence; moderation decisions are made by the founders." In 2019, Substack added support for podcasts and discussion threads among newsletter subscribers. Major writers on Substack include historian Heather Cox Richardson, journalists Matt Taibbi and Bari Weiss, authors Daniel M. Lavery, George Saunders, travel writer Blake Nelson and Chuck Palahniuk, novelist Salman Rushdie, tech journalist Casey Newton, blogger and journalist Matthew Yglesias, and economist Emily Oster. As of November 2021, the platform said it had more than 500,000 paying subscribers, representing over one million subscriptions. Substack announced in January 2022 that it would begin private Beta testing video on its platform. Finances Authors can decide to make subscription to their newsletter free or paid,