2006 - Inspiration
David Karp was surprised that none of the big names in blogging had produced a platform for "tumblelogs", short blogs, so began work on his own site with developer Marco Arment. Spotting a gap in the market may be one of the biggest buzz phrases in entrepreneurship, but David Karp did exactly that and was determined enough to run with it.
February 2007 - 75,000 users in two weeks
The demand for Tumblr's easy to use and clean blogging space was proven by the reaction of bloggers to its beta release. Using this small release as testing ground, but waiting to release a final product, mean Karp was able to enter his first funding round with proof of the potential of Tumblr.
October 2007 - Tumblr raises $750,000
In the first round of funding, Spark Capital and Union Square Ventures invested £750,000 in Tumblr, giving it the capital to launch and market itself globally. After a full release, the second round of funding in December 2008 went on to raise a further $4.5m.
February 2009 - First official app
Developers Jeff Rock and Garrett Ross actually created the first Tumblr app, Tumblerette, but Karp bought it and went on to release an official iPhone app for Tumblr later that year. The official app was crucial in Tumblr's struggle to surpass competitors including WordPress in the number of blogs posted on their sites.
June 2012 - First large scale advertising campaign
Five years after starting up, Tumblr was finally monetised and started allowing advertising on the site, with a huge campaign from Adidas. Having not generated money before, 2012 saw Tumblr receive £13m in advertising revenue. While still not enough to break a profit, it created interest in the potential of the business.
May 2013 - Yahoo buys Tumblr for $1.1bn
That interest led to Yahoo's huge purchase Tumblr. While the possibility of much larger advertising revenues will be a big drawing point, the move is also a signal of intent from Yahoo itself. If it is ever going compete against its rivals at Google and Facebook, Yahoo needs a presence in social media, and Tumblr is now that presence.