When you purchase a book on Amazon, you generally have two choices: Buy it directly from Amazon, or purchase it through Amazon but from a third-party vendor. If you go the direct route, Amazon has already purchased the book from a publisher and is holding it in an Amazon fulfillment center—a _______ transaction. If you take the third-party route, Amazon acts as an agent for the supplier and takes a commission of about 10 percent of the value of the merchandise for the right to sell it on Amazon’s platform—a ______ transaction.