Feedvertizer Plugin lets you add your own text-link ads to your feeds, you can even add the term “Copyright &,” in the plugin before the word, “Advertisements,” and it will actually have a constantly updated year after it! The plugin is based on Taragana’s Copyrightfeeds plugin.
Installation & usage:
- Download Feedvertizer plugin, and extract to a local folder.
- Upload feedvertizer.php file to wp-content/plugins/ folder.
- Activate from the Plugins page in WordPress Admin panel.
- Go to Options from the main menu and then click Reading from the sub-menu
- Under Syndication Feeds in For each article, show: select Full text and then click Update Options button.
Also see WordPress for more on adding stuff to feeds: