Synonyms: here you can set a list of words, and for each word you can add a series of replacements (synonyms).
When you apply the changes to your posts, BlogHatter will replace any* occurrence of the word with a random replacement in the list

Links: here you can set a list of anchor text, and for each of this you can add a Link replacement
When you apply the changes to your posts, BlogHatter will replace any* occurrence of the anchor text with the related Link

For example, if you add "Acid Reflux" as anchor and http://youraffiliateprogram.com as link, the result in the editor will be:

Acid Reflux

or

<a href="http://youraffiliateprogram.com ">Acid Reflux</a>

in the HTML code.

*You can set the max number of replacements BlogHatter will make for each post using using thi control:

0 = BlogHatter will replace all the occurrences
1 = BlogHatter will replace the first one (and only the first one) occurence
2 = BlogHatter will replace the first two  (and only the first two) occurrences
3 = etc...