David Karp was born in New York, New York in 1986 and even at an early age he showed a great interest in technology and programming. By the time he was 11 he taught himself HTML, short for hypertext markup language, which included how to format a system for text, graphics, and audio retrieved through the internet. At the age of 17 he left home to live in Japan for a brief period of time to become more in tune with that country’s knowledge of technology. But he returned to New York after a short time and got himself a job at UrbanBaby. When that site was sold in 2006 the makings of Tumblr began to start.
A beta was released privately in 2006 but not made available to the public until 2007. In the site users could format their blog posts with pictures, videos, audio, links, and almost anything that can be procured from browsing the internet. However, what made Tumblr unique was that there was not a “comment section” because Karp wanted to cut out “vandalism and mean-spiritedness”. What users could do in place of commenting is “reblog” posts from other users onto their own blogs. It only took five years for Tumblr to amass more than 70 million blogs. Tumblr was bought by Yahoo in 2013 for $1 billion but the following year it failed to meet revenue expectations and in 2017 Karp stepped down as CEO. While Tumblr is on its end of life during its peak it was one of the most unique and most used blogging websites and as of July 2019 it has over 472 million accounts.
https://www.britannica.com/biography/David-Karp
https://www.statista.com/topics/2463/tumblr/