Conditions - Devices
When designing overlays, its best practice to ensure that your design is coherent across all device types to reinforce both your messaging and your product offering. This also ensures that your always getting the best coverage.
You can determine which devices you want to target within Salesfire by the looking for Devices in the Conditions tab. Simply select the format and the overlay will be set to fire on those specific devices only.
Be aware; screen sizes between devices vary i.e a Desktop screen will be much larger than a tablet screen and even larger than the screen on a mobile device, generally with a much higher resolution.
With this in mind, it is best practice to create 2 or individual campaigns (one for Mobile and another for Desktop) to certify that your campaign appears and triggers on all devices as intended.
The dimensions for both campaign types is as below:
Breaking out each campaign by device also has the added bonus of having its own reporting, making it easier to analyse how that segment of your target market reacts differently.