Tumblr now automatically adds Buy and Pledge buttons to users' posts, similar to the experimental Buy buttons on Twitter and Facebook. One merely has to post links that lead to the ever-familiar Etsy or Kickstarter, or to the more obscure Artsy or DoSomething .And Tumblr will do the rest. We'll bet sellers would love being able to maximize their selling potential on Tumblr, especially now that holidays are approaching.
So if you hate seeing those types of posts, you'll just have to find unfollow button .