Doug M. Sanford of Vending Times notes that "many vendors today do not remember the urgency with which industry leaders called on their peers to install coin mechanisms that held the patron's money in escrow until the vend was made; to post a telephone number that a customer could call to report a failure and request a refund; to make sure their drivers were cleaning the machines adequately and replacing burnt-out lamps; and so on and on". More recent innovations include improved coin and bill validation and the rapid adoption of sense-and-feedback systems to verify that the vend was made.