What can I say back to reply to my peer to add to the conversation? The number of bills generated would be a better cost driver for a hospital's Financial Services Department because the more bills that this department generates and sends out, the more revenue the organization will make; the number of bills generated would also affect this department's costs (Reiter & Song, 2018). In addition, this would be a better cost driver because it would encourage cost reduction efforts and would be perceived as fair (Reiter & Song, 2018)