It may seem unusual to consider abandonment as a value extraction process. However many forms of intellectual property in particular patents and trademarks require continued maintenance and registration fees over their lifetimes. Abandoning this art saves payment of these expenses as well as the companies cost of internal personnel auditing and properly tracking the asset through its life.  For large patent estates abandonment can represent significant savings. In the 1990s the Dow Corporation had a very large patent portfolio and after conducting a portfolio mining exercise abandoned many of the patents that were no longer useful for the corporation’s businesses. In doing so they avoided almost $40 million in total expenses.