Note: "Auction overlap" is a tab you can access in Delivery Insights.

When your ad sets target overlapping audiences, they may end up in some of the same auctions. To prevent you from bidding against yourself, we remove all but the most competitive of your ad sets (based on past campaign data) from such auctions. Ad sets removed from a lot of auctions have high "Auction Overlap Rate" and may end up performing poorly because they don't have enough chances to be delivered.

What are the metrics involved?

Delivery Insights provides the following metrics to help you understand the impact that auction overlap is having on your ad sets:

• Amount spent: The estimated total amount of money that you've spent on your campaign, ad set or ad during its schedule.
• Auction Overlap Rate: The percentage of times this ad set was removed from the auction because it overlapped in the auction with another of your ad sets. Learn more about audience overlap.

  Note: Auctions occur at the ad level, but we show you aggregated data for the ad set, where audience overlap occurs.

• Overlapping ad set: This identifies the ad sets (indicated by their ad set IDs) that are causing your selected ad set to get removed from auctions most often. The percentage indicates how much of your total Auction Overlap Rate is due to audience overlap with the given ad set. For example, if your Auction Overlap Rate for a given ad set is 50% and an overlapping ad set shows 50%, it means that your ad gets removed from auctions 50% the time, and 50% of the times it gets removed is due to this ad set (in other words, 25% of the total lost delivery opportunities).

  This number can be useful when figuring out how to merge ad sets. For example, it'd probably be more effective and efficient to merge a poorly performing ad set into one that's leading to 75% of its auction removals rather than one that's only leading to 5% of them.

  Note: This number refers only to the percentage that an ad set contributes to your total overlap, regardless of how much or little there is. For example, if your ad set's Auction Overlap Rate is only 5% overall, one ad set could be contributing to 50% of that overlap. You'll find more information on this in the next section.

What should I do with this information?

It can help you determine whether your targeting is leading to performance issues. If it is, we recommend the following actions:

• Merge ad sets with high overlap rates into ones that are causing the high rates. Start by checking whether an ad set has a high Auction Overlap Rate. If it does, check the ad set's "Overlapping Ad Set 1". If it accounts for a significant portion of the auction overlap, it's probably a good idea to merge the low-performing ad set into it.

  Here's an example scenario: After seeing that an ad set targeting fans of your Page has a 50% Auction Overlap Rate, you check its overlapping ad set 1. You find that it's an ad set targeting people who visited your website and that it's accounting for 60% of the auction overlap. You decide to merge the Page fans ad set into the website visitors ad set. You do this by adding the budget and targeting of the former into the latter. That way you maintain data from the successful ad set, which means it could take less time for it to adjust to the new settings after the merge.
• Use targeting exclusions when possible. Making your audiences distinct can help prevent auction overlap before it happens. For example, if a specific audience overlaps with a broad audience, consider excluding the specific one from the broad one, whether when creating the audience itself or during ad set creation using exclusion targeting.

What if I want my audiences to overlap?

Audience overlap is not an inherently bad thing. For example, if you have two ad sets with broad audiences that overlap a lot but have low budgets, they may never end up in the same auctions. Audience overlap always precedes auction overlap, but doesn't necessarily lead to it. Auction overlap is what's actually problematic, not audience overlap. If your strategy involves audience overlap, monitor these metrics to ensure that it doesn't become a problem.

Learn more about audience overlap.

* Nguồn: Facebook