We advise you to review the Ultimate Guide To Textbook Arbitrage so you have a full understanding of what it is about and what it entails. The two products are very different, but they are marketed similarly according to our study. It seems clear that Zen is a knock-off of the Book Profits system as they put together a cheaply made product with product support that is more miss than hit, and rode the coattails of the Book Profits founders with their advertising and made up wild, outlandish stories of hack attempts, which are laughable by a person with the least amount of common sense.