As enterprises equip more employees with PDAs, they must understand the total cost of ownership (TCO) for these devices. Gartner, Inc. analysts said the TCO for a PDA per user can approach $3,000 a year. TCO for a wireless device will mostly add additional hardware, software, and service costs on a per-user basis compared to mobile (but not wireless-enabled) devices. Additional software and service costs can vary, but average about $50 per month per user. Gartner found PDA TCO approaching $3,000 per user per year. Adding a wireless modem with a TCO of $1,392 will bring the cost to $4,392, comprised mostly of hardware, support, and additional service fees.