Tumblr’s blog-like function allows account-holders to use the platform in order to create diaries of their daily lives, to post different types of information that inspires them, as well as to liveblog about events as they happen or about TV shows as they are aired. The platform supports seven different types of posts, such as text posts, whether plain or accompanied by images, hyperlinks or videos, but also photo posts, quote posts, link post, chat posts, audio posts and video posts, whether uploaded from a device or imported from websites such as Vimeo or YouTube. The social media function allows users to “like” and/or reblog a post. Another function permits communication between different accounts, although users can also chose to keep their content private. The website uses the followers-based system made famous by Twitter, where interested users can follow other users' blogs, whether they are friends, strangers or even celebrities. One of the most well-known Tumblr accounts is that of the White House, which shares both formal and informal posts, such as GIFs of now former President Barack Obama singing or the First Lady’s workout plan.
Due to its fast-pace communication style, multiple mediums and heavy use of sometimes specific imagery, pop-culture references and slang, Tumbler is unsurprisingly most popular among young Millennials. As of December 2016, almost half of Tumblr users in the United States were aged 34 years and younger, with 18 to 24 year olds accounting for 25.7 percent of U.S. Tumblr audiences. There are currently more than 23 million Tumblr users in the United States. Despite Tumblr being a relatively niche social network, its users are highly engaged - U.S. Tumblr app users spent an average of almost 210 monthly minutes on the social app, ahead of arguably more popular industry leaders Instagram, WhatsApp and Twitter.
Tumblr, which was named one of the most valuable startup companies based in New York, generates revenue with the aid of paid advertisements on the website. As of 2015, Tumblr creator and CEO, David Karp, who was named by MIT as one of the top 35 innovators in the world under the age of 35, has an estimated net worth exceeding 200 million U.S. dollars.