Campaign budget optimisation (CBO) makes the most efficient use of your budget spending to get you the overall best results, and ensure that the cost of those results align with your bid strategy.

A campaign budget is a budget set at the campaign level (rather than the ad set level). The amount you set can apply to each day the campaign runs (daily budget) or over the lifetime of the campaign (lifetime budget).

How it works

CBO uses your campaign budget and bid strategy - which can be, for example, lowest cost per action (CPA) or highest return on ad spend (ROAS) - to automatically and continuously find the best active opportunities for results across your ad sets.

You can create ad sets that have different start and end dates or times, as CBO considers each active ad set's schedule (ads can run all the time or on a schedule). However, CBO may not spend your budget equally for each ad set, as Facebook optimises for your overall campaign budget.

Bid Strategies: Cost Control

Bid strategies are overall approach to spending budget and getting results. The long-term success of your campaign relies on keeping it profitable. It is important to never bid more than an action is worth so that you can maintain profitability.

1. Lowest cost (auto bid)

• Facebook manages bidding
• No control over your cost
• Reach all lowest cost opportunities while spending your budget
• Want to spend full budget

2. Bid cap

• Need to spend more time managing bids to control cost
• May not spend full budget

3. Cost cap (50% availability)

• When you want to maximise cost-efficiency
• Minimise your cost when possible without manually adjusting your bids
• Cost may rise as you run out of cheapest opportunities
• May not spend full budget once you hit the cap

4. Target cost

• When you want to maintain a consistent cost
• Lose out on all cheaper results
• May not spend your entire budget

Difference between cost cap and target cost

Both bid strategies use an average cost control as a benchmark, but aside from that, they work differently. A cost control using target cost bid strategy is an amount to stay close to even if there are lower cost optimisation events available. A cost control using cost cap bid strategy is an average amount to stay under while still getting the lowest cost optimisation events first.

Difference between cost cap and bid cap

Cost controls using cost cap bid strategy are more flexible, which means they are less likely to constrain delivery than bid controls. Cost controls apply to your average cost per optimisation event, so Facebook can pursue opportunities across auctions at a wider range of costs. Some optimisation events cost more than your cost control, over the lifetime of your ad set your average cost should be at or below your cost control amount.

Bid controls using bid cap bid strategy are less flexible, which means they are more likely to constrain delivery than cost cap. Bid controls limit what Facebook can bid in every auction. You should use a bid control over a cost control only if you have to control the cost of every optimisation event you get.