Someone else may have already noted this, but it took me four days to realize the game-changing potential of the upcoming Public Notes feature Amazon is bringing to the Kindle. If authors and celebrities take to it the way they’ve taken to Twitter, they could create entirely new marketing angles (bleh), as well as entirely new virtual editions of ebooks (whaa?). And the benefit for Amazon could be the creation of added value that no other ebook store can currently match.

Take for example a book on American politics, not because that kind of book is fun to read, but because such a book always has two characteristics: a strong point of view that practically begs for counter arguments, and debatable errors either in actual facts or in the interpretation of them.

With Public Notes, now a noted public figure of an opposing political bent can read and annotate a Kindle edition of a new book by someone on the other side of the argument, and the reading public can tune into that person’s highlights and notes from within the original text.

It’s a virtual annotated edition, and one that only exists temporarily. The author of the notes can remove them or disable public access to them at any time, or a reader can choose not to follow their annotations the same way I don’t follow certain celebs on Twitter.

Earlier this week I was laughing to myself about how much fun it would be to add funny or satirical notes to someone’s book, but the big problem was that almost nobody would want to read my notes.

But if Glenn Beck were to annotate Rachel Maddow’s book, and Rachel Maddow were to annotate his, I bet you’d have a considerable amount of interest from consumers. You’d probably sell more of each book to readers who would normally avoid your book.

For now, this seems more compelling to me with nonfiction categories like politics, memoirs and media/journalism criticism. But I can imagine too that public annotations from authors could be used by publishers as a sort of “blurb on steroids” — the key difference being that annotations are actually added content, and therefore added value, that only Kindle editions can currently offer.

And then there’s the possible bad news: will publishers and authors freak out over this? Do they understand its potential? Will the Authors Guild, or some executive, or a famous author accuse Amazon of producing new works, and therefore infringing on copyright? My guess is yes, and like text-to-speech the feature may get hobbled before it can really take off.

But since I think this can sell more books in the end, I’m hoping that everyone involved on the publishing side of the business embraces it wholeheartedly. And, while I’m blue-skying this stuff, that Amazon hasn’t managed to somehow patent it.

Via Chris Walters’ BookSprung blog