Figured it out -- Adsense for Feeds on Blogger

For anyone that’s trying to add Google AdSense for Feeds to their Blogger site:

• Log into Blogger.com.
• At your Dashboard, select the blog to which you are trying to add the AdSense for Feeds.
• Click the “Settings” tab.
• Click the “Site Feed” sub-tab.
• Copy the AdSense for Feeds code out of your Google AdSense site (note that you must be signed up for AdSense and have received activation of AdSense for Feeds in order to access this code).
• Paste the AdSense for Feeds code into the “Article Footer” box.
• Click “Save Settings.”
• Click “Re-Publish Index” once it says your settings have been saved.
• Do a test post and view it through a feedreader like Bloglines to ensure that everything worked correctly.

Note that unless you paste the AdSense for Feeds code into your Blogger template, the ads will not be visible on the HTML version of your site.