For example, in the United States, the patent rights given to pharmaceutical companies encourage them to charge high prices (above marginal cost) and to advertise to convince patients to persuade their doctors to prescribe the drugs. Likewise, copyright provides an incentive for a publisher to act like The Dog in the Manger, taking older works out of print so as not to cannibalize revenue from the publisher's own new works. Examples from the entertainment industry include Walt Disney Studios Home Entertainment's "vault" sales practice and its outright refusal to issue "Song of the South" on home video in most markets. Examples from the computer software industry include Microsoft's decision to pull Windows XP from the market in mid-2008 to drive revenue from the widely criticized Windows Vista operating system.