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This optimization allows you to exclude all the low-performing mobile app placements that are costing you money but not resulting in any conversion.

The tool will list out all your mobile app placements with exactly 0 conversions in the last 30 days and with costs greater than zero.

You can exclude both types of automatic placements; for IOS and Android apps at the ad-group level in bulk.

You can access the tool here and the detailed user guide here.

With the Display Placements Exclusion optimization, you can find placements that are resulting in wasted spend and exclude them based on a business goal – Branding, Traffic, or Conversions. This tool also makes it possible to see sites that are part of search partners and exclude them.

You can access the tool here and the detailed user guide here.

Excluding placements from an account helps prevent your ads from showing up on certain placements on the Display network or YouTube, overriding any campaign-level placement targeting.

For some cases, as with Smart Shopping and Smart Display campaigns, account-level placement exclusions are a great solution, as Google doesn't support excluding placements through a negative list or by excluding them at the ad group level.

You can access the tool here and the detailed user guide here.