Although Tumblr has only been around for about four years, the microblogging platform now hosts most blogs than Wordpress.com. As recently as January of this year, Tumblr was home to just 7 million individual blogs. However, that number has ballooned to more than 21 million blogs today. While Tumblr’s growth has always been impressive, it hasn’t come without pitfalls. Last December, Tumblr experienced a monumental crash, causing the site to be down for approximately 24 hours. Since then, the company has focused almost entirely on scaling. New features were put on hold as Tumblr hired executive…