Facebook launched Campaign Budget Optimization at the end of 2017, which will need to be done in the Ad set before it can adjust its budget.

With this feature, budget adjustments can be made at the campaign level, which shows that Facebook's algorithms are really getting smarter.

Campaign budget optimization is used to optimize the allocation of campaign budgets between ad groups. This means that Facebook automatically looks for the best opportunities to achieve results among ad groups without interruption, and allocates campaign budgets in real time to achieve those results.

Xiao Yi provides another clue that the number of similar audience reach (which of course requires going to the ad group level to get a specific number of reach) is 2 million, and the number of interest audiences is 500,000.

If you allocate a 1:1 budget to both groups during the testing phase, it's not fair to 2 million similar audiences, because the ads are much less likely to reach than the interest audience.

So it's appropriate to allocate a budget in proportion to the number of audiences, based on which the ad group's budget ratio should be 4:1.

When you create a campaign, you light up budget optimization, and you'll have options for budget optimization - your campaign's total budget and campaign auction strategy.

The total campaign budget will be used for all ad groups, just to see which ad group budget is allocated how much difference, more ad groups, the total budget of the plan will naturally be more, how much total budget to give, or based on the previous data and the budget for a single ad group, and then these budgets for a single ad group add up to a total budget size.

With regard to bidding strategies and the default settings that are recommended for illustrations, Facebook's algorithm ensures that you get as much results as possible at the lowest cost.

Once you've optimized your budget at the ad level, you can also take more control of your budget at the ad level, so try to see how your budget settings change when you select Daily Budget and Lifetime Budget at the ad budget level.

Regarding this question, due to different factors, there is no definite answer, Xiao Yi suggests that you pass the test to verify that this feature is suitable for you.