pskl.us has a tutorial on configuring blog publishing on the Kindle. Covers all the steps, but doesn’t mention the need to remove all advertising and commercial links from the content (because pskl.us has none, he didn’t run into it). The terms and conditions of the Amazon Kindle Publishing for Blogs requires it:
You will deliver a full text, well formed XML feed of each publication from which you have removed all advertisements and other materials that are primarily intended to advertise or promote products or services and from which you have removed all video and / or user-generated links (e.g., Reddit, DIGG, and Technorati).