Sometimes you might want to prevent two ads from running next to each other. The classic example is two competitors who don’t want their messages side by side.
With Google Ad Manager, you do that with a “competitive exclusion” label. Two ads with the same competitive exclusion label should never run next to each other.
Add the label
Find labels on the left under “Admin > Inventory”
Add a new label, give it a name, and make sure to check the “Competitive exclusion” checkbox.
In the line items you want to exclude from showing next to each other (under “Delivery > Line items”), add the label to “Labels” in the “Additional settings” section.
Optionally, you can enable the “same advertiser exception”, which allows ads with this label to run next to each other as long as they are all from the same advertiser.
Make sure you add the same label to all the ads you want to prevent from running next to each other. (In other words, if you want “Ad A” from Company A and “Ad B” from Company B to never run next to each other, you must add the same competitive exclusion label to both the “Ad A” and “Ad B” line items.