The website announced news that it's raised $85m in a fresh round of investment that included Branson as well as a host of major companies.
As always, the 61 year old, whose Virgin empire has over 400 businesses, isn't afraid to try his hand in attempting to grow another in a new industry.
The funding proves that even in a time of economic turmoil there are opportunities for companies to record massive growth. CEO of Tumblr David Karp said last June that the service had hit 400 million page views in a single day, which translates into around 5,000 page views a second. All this has led to Business Advisor valuing the company at $800m.
But Branson's involvement doesn't guarantee further success for Tumblr. Throughout his long career in business, the Virgin Media mogul has had a few mishaps. Most notably Virgin Vodka (yes that happened) and Virgin Cola (this worried Coca-Cola for around five minutes).
However, with 30 million blogs currently calling Tumblr their home, we're sure that Branson's investment is a safe one.