If you have multiple ad setsAn ad set is a Facebook ads grouping where settings like targeting, scheduling, optimization, and placement are determined. More that attempt to enter the same auctionFacebook uses an ad auction to determine the best ad to show to a person at a given point in time. The winner of the auction is the ad with the highest total value, based on bid, estimated action rates, and ad quality. More, the algorithm will choose the ad with the highest total value. This is Auction Overlap. The other ads won’t be considered.
This is most likely to happen if you have multiple ad sets targeting the same people. Auction OverlapAuction Overlap can happen when you have two ad sets running at the same time, targeting similar audiences. When their ads are about to enter the auction, Meta first chooses the ad with the highest total value. That ad will be the one that enters into the auction. The other won't be considered. Meta does this to prevent you from bidding against yourself. When there's too much Auction Overlap, it can result in higher costs or under delivery. More is meant to prevent you from competing against yourself in the auction.
When is This a Problem?
On a small scale, this is unavoidable and won’t lead to noticeably bad results. But, it’s a problem if it happens often.
Auction Overlap is good for the surviving ad set because it won’t compete against another one of your ad sets in the auction. But the competing ad set that is repeatedly prevented from entering auctions might struggle to spend your budgetA budget is an amount you're willing to spend on your Facebook campaigns or ad sets on a daily or lifetime basis. More. Or your budget will spend, but it will cost more to show your ads.
Too much auction overlap will make performance less stable and predictable, especially when scalingScaling is the process of increasing your budget or focus to get more results from an effective campaign or ad set. Advertisers often speak of vertical scaling (increasing your budget) or horizontal scaling (increasing your targeting audience) to achieve these results. More. It may make it more difficult to exit the Learning Phase. This, obviously, is not preferred.
What Should You Do?
First, when Auction Overlap becomes an issue, you should see Delivery Recommendations to combine ad sets. You should consider doing so when it makes sense.
Second, you can create an Automated Rule to either combine ad sets dynamically or alert you when Auction Overlap is detected.
The alert may be preferred to give you the option of combining ad sets or not.
Bottom line: Avoid Auction Overlap by limiting the number of competing ad sets that target the same people. This is far more common now because of Advantage+ Audience and Advantage audience expansion. Even if you don’t intend to create ad sets with overlapping audiences, they often will.
This is why I continue to recommend limiting the number of unnecessary ad sets. It’s what Meta wants, and it will often lead to better and more efficient results.
