How to add Adsense on a single post [Tumblr]
I figured out how to put adsense on my Tumblr blog. With adsense, there are some restrictions and rules. Make sure you read up on those before you attempt to add it to any site. You don’t want to lose access to adsense once you’ve been approved. One of the restrictions that is important to remember is the number of ads you can have per page. It depends on the type of ad you have too.
If you look at my home page, you’ll see the skyscraper ad on the right sidebar. If you look under the top 2 posts, you’ll see simple link units. That’s all that shows up on my homepage because of the ad limits. In the picture below you can see the link units.

Something I wanted to try was having ads appear when you click on the permalink for a post. This way, the ad will show up on just the post pages and not disappear because I’m over the limit. In the picture below you can see what that looks like. It shows a link unit, a skyscraper in the sidebar, and a square below the post.

I found a post from Just Nuggets that mentioned following the structure of Disqus. This makes sense because Disqus comments only show up on the post page. This person found what worked his/her theme but it’s not the same everywhere. Generally speaking, you’ll want to put it at the top of the [block:PostNotes] section and before [block:PostNotes/]. You may have to play around a little to get the alignment right.
[block:PostNotes]
Google adsense code here
[block:PostNotes/]
Mine looks like this because I wanted it centered.
[block:PostNotes]
<center>
Google adsense code here
<center/>
[block:PostNotes/]
If you have any trouble with this let me know or do some digging on google.