Tumblr is one of the earliest iterations of all of social media. You can say that Tumblr was one of the founding members of it. If you ask me, Tumblr is like the big brother of twitter, they had the same concept, however, Twitter is more about short messages. They both have merits of their own, however, Tumblr did not try to evolve in this modern era. It continued to do the same thing, which eventually bored the people that are using it.