Optimized Cost Per Mile is an Ad Set for biding on Facebook, which is used to drive conversion on a specified budget. This method lets you use facebook{s extensive data points, and the system is placed so you spend as much money as you can, but with great delivery rates. Facebook recommends a target audience of 1 million from which they expect an average of 25 conversions per day, a smaller target audience is not advisable by Facebook. Start OCPM here.