Originally Posted by Paul Markham

Content drives traffic, you would think after 20 years online some of you would have got the message. Do people crawl Tumblr for porn articles? Do people ask Search Engines for links to porn sites?

So no porn on Tumblr means no traffic from Search Engines who will send the traffic elsewhere. Which means it will all even out in the end all you have to do is a bit of work moving your articles.