When using campaign budget optimization (CBO), we recommend the following best practices to boost your campaign effectiveness

• Don't create more than 70 ad sets per campaign. Doing so could limit what you can do after publishing. Also, it's important to remember that the more ad sets you to include in a campaign, the more time it will take to learn how to manage them.
• After adding all the ad sets that you need, it takes about 2 hours for the CBO to adjust.
• If you manually pause or unpause your ad sets, it will prevent your campaign from focusing on the active ad sets within your budget.
• The more ad set spend limits you set, the less flexibility your campaign has to work with. Doing so can help you avoid having to pay more than you should, or maybe even not deliver at all.
• If you adjust campaign settings, your campaign's input changes may be in bulk to minimize the time spent during the learning phase.
• If your audience size is significantly different from the largest advertisers, your ad sets may receive less budget with CBO.
• Stop setting low delivery ad sets on low delivery days and prevent CBO from finding tomorrow's opportunities. This can increase your cost per action (CPA) and prevent you from finding tomorrow's opportunities.
• If your ad sets are not delivering, it could affect your campaign's effectiveness. This is why it's crucial to ensure that all ad sets are delivered.
• Instead of analyzing results at the ad set level, focus on the campaign level.