People post other things on Tumblr besides GIFs and sob stories, you know -- some even use it to promote their handmade goods or crowdfunding projects. It's those users who'll benefit from this update the most, because the website 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 (an online auction house) or DoSomething (home to campaigns that "make the world suck less"). And then, well, 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 that other button labeled "unfollow."