I purchased the eBook version via the Sony Reader Store and it too doesn't contain a code, only a reference to an inner cover that's not included.
I've just finished reading the book and I think it's a nice read. The ending is a bit abrupt and some situations are a bit hard to believe, most especially Geni's reaction to Jacob, Nym's sudden almost-change of heart and Balu'thia coming on to Xander. The Iru seemed like an interesting addition, but the encounter really seemed to serve no purpose, there didn't seem to be a real reason to include it. The book also contains quite a few punctuation and grammatical errors. But I think it's a decent debut and I'd read the next novel.