Many of those who have never lived in a textbook-adoption state have never really understood the concept of "book depository." Depositories exist in many of the approximately two dozen textbook- adoption states. Florida is one of those states, and it is a major force in the national instructional materials market. The Florida book depository is a private for-profit company that maintains a 300,000- square foot warehouse and an inventory of 21,000 items, including state-adopted and non-adopted materials. To understand book depositories, one must understand the "most-favored- nation" legal clause, which requires publishers to provide every textbook-adoption state with the same best offers as were made to any state or district within the United States. The law does not automatically ensure that all states receive identical prices, because the requirement governs prices only in the year that the contract between a state and a publisher is established -- and publishers tend to raise prices each year. This article describes the functions of "book depositories" and how they work.