To avoid overspending, what *criticalsetting must be configured to limit campaign ad spend and ensure you only pay for what you are actually going to gain?

To avoid overspending and ensure you only pay for what you are actually going to gain, the *criticalsetting that must be configured is the campaign budget and potentially a bid limit, depending on the bidding strategy used. The campaign budget sets the maximum amount you are willing to spend on a particular campaign over a specific period (daily or lifetime). By setting a budget, you prevent the campaign from exceeding your allocated funds. If you are using manual bidding strategies, it is important to then set a maximum bidding threshold. This ensures you aren't paying excessive amounts for each click or impression, but the hard budget ensures at least you don't exceed the limit. If you're using automated bidding, ensure the Target CPA or Target ROAS is achievable and regularly monitored.