Tumblr
Installing AddThis to your Tumblr blog is easy. This visual guide will walk you through the installation process. First be sure to Get AddThis for Tumblr, then follow the steps below.
Blog Post Button
If you'd like to place the button in your Tumblr blog, follow these directions. This plugin will automatically insert the AddThis button below each post in your blog.
Step 1
In your Tumblr dashboard, click Customize.
Step 2
A preview of your blog should load. On the top navigation, click Theme, and a drop down menu will appear.
Step 3
At the bottom of the drop down menu, click on Use custom HTML. The thumbnails of the templates will be replaced with a screen of HTML code.
Step 4
In the HTML code, search for <div class="bottom"> using your browser's find feature.
(commonly in Edit > Find)
Step 5
Right before that line, copy and paste the code from AddThis.
Step 6
Finally, click Save Changes in the far right on the top navigation. You're done!