Let's add our back geo for our Device ID campaign. This should be where your ads are served so long as they are served to the device ID that you are targeting. Ideally, your back geo should be farily large.
For example, if I am targeting all device IDS that went to my competitor locations within a 5-mile radius, I don't really care where that device is when they see the ad, so long as they see the ad. So I may select DMA, state, or larger as my geo here.
Learn more about [back geos here >>](https://support.ui.marketing/what-is-a-device-id-back-geo)