With the introduction of their unlimited subscription program, Scribd implemented a system to manage the available titles in their catalog based on a number of variables, including cost. This was done to offer subscribers a broad selection of titles while minimizing the risk that payouts to publishers will become unsustainable. As a result, Scribd might remove some titles from their catalog without further explanation.
Scribd reserves the right to manage the catalog of content they choose to make available, so their removal of titles (due to cost or other reasons) is out of our control. However, Scribd advised that removed titles may have a better opportunity at becoming part of the rotating catalog if they are offered at a lower cost (but this is not guaranteed).