Patent maintenance fees continue to increase. However, once the patent has issued, the USPTO does not provide any ongoing services to the patent holders. Therefore patent holders are correct in wondering why they must pay patent maintenance fees and why the fees are increasing. The requirement of maintenance fees has both economic and public policy reasons. First, maintenance fee revenue is used to fund the operations and expenses of the USPTO such as the examination of new patents. Second, maintenance fees allow for the promotion of progress of science and useful arts.