From the Tumblr Staff weblog:
On Thursday, we’re going to introduce ads on Tumblrs, so that later this year people can start making money from their blogs.
Tumblr is a place where brilliant, creative, funny, impossible people shape culture. Some of you have even turned your passions into jobs: book deals, music careers, paid gigs with the Creatrs program. Now, (soon!) that opportunity will be available to any eligible Tumblr—poet, musician, fan artist, and misfit weirdo memelord alike.
It’s fascinating that a service as old as Tumblr has gone this long without an advertising platform. The service is nearly ten years old and features one of the most vibrant communities on the Internet. I would have expected something like this shortly after their acquisition by Yahoo in 2013. But here we are, three years later, and it’s just now launching.