Apple not allowing iBooks with Amazon links

Apple's new iBook service lets authors self-publish, but as one author found out you better not link to Amazon in your text.  Seth Godin's iBook submission was rejected by Apple not because he had objectionable material, but because he linked to Amazon's bookstore.  We've seen similar policy with iOS apps not being allowed to point to an outside link to purchase a subscription (effectively getting around Apple's cut), but keep in mind that Mr. Godin wasn't linking to his own book on Amazon.  The links were to reference material used in his book, and they pointed to printed editions of the books that aren't available in digital format or from Apple.  iBooks is a very cool way for authors to get their work out that otherwise couldn't, but this is just another example of Apple ruling their ecosystem with an iron-handed, irrational fist.