According to Santa Cruz County, California, exchange staff interviewed by "Santa Cruz Local" in 2019, it is a common practice for exchanges to not count, but approximate the returned sharps by "eyeballing" the volume. Holyoke, Massachusetts, also uses the volume system. United Nations Office on Drugs and Crime for South Asia suggests visual estimation or asking the client how many they brought back. The volume based method left potential for gaming the system and an exchange agency in Vancouver devoted significant effort to game the system.