In a new update, RollerAds added Custom Bids, a feature that will help you further customize your ad campaigns. This tool is designed to test zones separately and optimize your costs.
You can choose any number of desired zones to set up your own values for custom bids.
To do this, simply add the zones you want to focus on in the line after the CPC value in custom bid. You can write them down in a row manually or copy and paste the best performing ones from the Statistics menu.