On how important social media has become, Karp shared that the bulk of traffic that Tumblr sees comes from Twitter and Facebook. Not Google. This isn’t surprising, but speaks volumes about the real-time value of Tumblr. While most blogs rely on Google for the bulk of its traffic, Tumblr has carved itself a niche that is a hybrid between real-time and static content. Basically, the company has built the best of both worlds.