Conditional targeting settings is an additional targeting feature. By supporting these scenarios, header bidding can be more efficient - the browser can send bids to a more surgical set of bidders based on device size. Using these feature will be very appropriate in case you have multi size in GAM (formerly DFP) account. Moreover, it is quite easy to set up: you just need to create condition card with screen width, add it to the unit configuration in buyer’s settings and select certain parameters for this condition if required.
Let’s take it step by step:
By hovering on the name of your account in the upper right corner you will see a drop-down list with the tabs, click on the “Settings” tab.
Click on the Add Condition button (1) to create a new condition. Then enter name (2) of condition and select sizes (3). In the size’s fields you have to select minimum and maximum screen width. E.g. there is a slot with sizes 970x250 for desktop but 728x90 on the tablet, you have to enter min and max sizes, you use for the tablet (for example, from 301 px to 800 px).
Press the Create button (4) to save your condition.
Go to the buyers tab and select buyer. Click on the Ad Unit (1) and on created unit (2). Now you are able to see the condition card. Select the condition from the drop-down list (3). If some bidders have different parameters for different devices (sizes), click on the Add parameter button (4), enter parameter name (5) and parameter value (6). Click on the Add Condition button (7) once again to create an additional card, in case, you want to enable few conditions for the unit.
Press the Save button (8).