A memorable and catchy phrase makes for a good Tumblr blog URL. Using too many numbers in the blog URL can make it difficult to remember and less likely to be widely shared. Tumblr blog names need not be short, just easy to remember. One of the most popular Tumblr blogs in 2013 was "Reasons My Son is Crying," which is hardly a short name for a blog.
A Tumblr blog URL should also be descriptive; people should be able to tell what the blog is about simply by reading the URL. Tumblr is different from other social media platforms in that most Tumblr blogs are single-topic. Unlike more general-purpose Facebook pages and Twitter feeds, Tumblr blogs tend to be focused on one specific niche that they cover extensively. Choosing a vague and nondescript name for a Tumblr URL makes it difficult for the writer to stick to that one theme and difficult for readers to follow.
Common themes that succeed on Tumblr include Minecraft, fashion, comics, reaction GIFs and movie quotes. Blogging one's suffering using creative visual representations is also very popular. One of the top 10 blogs on Tumblr as of 2014 is about the difficulty of trying to find decent housing in New York City.