Pros and Cons: Meta Cost Controls
Despite what the prevalence of an endless stream of "advanced Meta strategies using cost controls" might have you believe, here's something that might surprise you: for most e-commerce advertisers, Meta's default Highest Volume (formerly Lowest Cost) bidding is a great option to use.
No caps, no controls - just let the algorithm do what it does best: find you the most conversions it can. Yet the allure of cost controls like Bid Cap, Cost Cap, and Target ROAS is strong, especially when you're watching every penny of ad spend or trying to hit specific profitability targets, targets that can often seem out of reach.
The key isn't choosing the "most sophisticated" strategy; it's knowing when these cost controls actually improve performance versus when they're just handcuffing Meta's algorithm. In this guide, we'll explore why Highest Volume bidding should be your default starting point, identify the specific scenarios where cost controls genuinely add value, and give you a practical framework for knowing when it's time to add guardrails to your campaigns…and when it's not.
Before diving into when to use cost controls (or not to), let's establish what each option actually does. In addition to Highest Volume, Meta offers three primary cost control mechanisms, each with distinct mechanics and implications for your campaign performance.
Highest Volume: Your Default Starting Point
Highest Volume is Meta's default bidding strategy - and for good reason. With this approach, you're essentially telling Meta: "Here's my budget, get me as many conversions as possible for that money." The algorithm dynamically adjusts bids in real-time, competing aggressively when it spots high-intent users and pulling back when conversion probability is lower. There are no artificial constraints, no caps to bump against, no targets to chase. As long as you have strong creative and a good offer, this flexibility allows Meta's machine learning to operate at full capacity, often resulting in strong results.
Bid Cap: The Hard Ceiling
Bid Cap is a bidding strategy whereby you tell Meta the absolute most you are willing to pay to bid for an expected action (typically a purchase) in the auction. Note that you are not setting a hard bid by impression, but by action. For example, if your breakeven CPA is $40 you could set a bid cap of $35, ensuring that Meta will not bid over $35 for any conversion, even if it thinks there is an opportunity to convert at a higher bid. While this gives you precise control over auction-level spending, it also means you might miss out on valuable conversions that would have cost slightly more but delivered strong returns. It can, however, effectively control costs.
Cost Cap: The Average Target
Cost Cap (now labeled "Cost per Result Goal" in Meta's interface) takes a more flexible approach. Instead of controlling individual bids, you're setting a target average cost per conversion. Tell Meta you want a $25 Cost Cap, and it might pay $35 for one high-value customer and $15 for another, as long as your overall average stays around $25. This gives the algorithm room to pursue a few more conversions than with Bid Cap, while balancing them with cheaper opportunities. However, it still puts constraints on the auction that can cause you to miss out on potential conversion opportunities.
Target ROAS: The Revenue Focus
Target ROAS (Return on Ad Spend) shifts the conversation entirely from costs to returns. Instead of saying "don't spend more than X per conversion," you're saying "make sure every dollar spent generates at least Y dollars in revenue." Set a 3.0x ROAS target, and Meta will optimize for purchases that maintain that return ratio, typically prioritizing higher-value purchases over volume. Of note, Target ROAS is only available when you use Maximum Value of Conversions as your performance goal, whereas Bid Cap and Cost Cap are your options when using the default Maximize Number of Conversions performance goal.
As with Bid Cap and Cost Cap, Target ROAS is putting a constraint on the auction, telling Meta if you don't think you can achieve my ROAS goal then don't spend.
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Highest Volume: The Place To Start
For many advertisers, and particularly those starting new accounts, Highest Volume is the best option to begin with. It gives Meta the most freedom to find conversions, it establishes a baseline of performance, and provides advertisers with cost certainty as you know what Meta will spend on a weekly basis (note: even though you set a daily budget, Meta gives itself license to go above or below that by up to 75% as long the 7 day spend matches an average of your set daily budget).
Meta's machine learning system is remarkably sophisticated, processing thousands of signals about each user - their browsing history, purchase behavior, engagement patterns, time spent on specific products, and countless other data points we never see. When you use Highest Volume bidding, you're giving this system full freedom to act on those insights. Add a cost control, and you start to put limits on this system.
Additionally, there can be a "Meta halo effect" whereby Meta ads, even if they do not lead to attributable conversions in platform, start users on a purchase journey that can result in higher direct or organic search conversions. When you place a strict control on Meta, you are forcing it to only spend when it thinks there is a likelihood of attributing conversions at your goal (usually within 7 days). This can restrict Meta from getting in front of users who could very well end up purchasing outside of Meta's attribution window. In other words, you are specifically telling Meta to exclude people who very well could be your customer, just because they are not immediately ready to convert.
When Cost Controls Make Sense
While Highest Volume bidding should be your default, there are legitimate scenarios where using cost controls improves outcomes. Here are some of the best use cases:
When Lowest Cost Performance Deteriorates
Sometimes Highest Volume bidding starts strong but gradually becomes inefficient. Or, it doesn't even start strongly at all and you find yourself consistently losing money. You might notice your CPAs creeping up week over week, or your ROAS slowly declining despite no changes to your ads or targeting. This often happens when Meta's algorithm gets "comfortable" spending your budget at increasingly higher costs, especially in competitive markets or during peak seasons.
In these cases, implementing a bid control at or slightly above your target CPA can act as a reset button, forcing the algorithm to find more efficient conversion paths. For example, if your Highest Volume campaign has drifted from a $30 CPA to $45 over several weeks, setting a $35 Cost Cap might sacrifice some volume but restore profitability.
Note however that cost controls aren't a magic wand that will suddenly achieve a CPA lowest cost never could. It may allow you to only spend on lower cost conversions, but in the same example above, if your CPA has ranged from $30 - $45, setting a cost cap of $25 won't magically allow Meta to suddenly find $25 conversions for you. If you really need your CPA to be lower than you have gotten it on Meta your best bet is to adjust the creative, offer, or landing page. Cost caps (or bid caps) can force Meta to spend more efficiently, but won't make your creative, offer, or landing page magically more effective.
When Margins and Efficiency Outweigh Scale
Not every business needs or wants maximum volume. If you're selling products with razor-thin margins, fulfillment constraints, or specific profitability requirements, preserving efficiency becomes more important than capturing every possible conversion. This is particularly true for:
• Low-margin products where a few dollars difference in CPA swings you from profit to loss
• Limited inventory situations where you can only fulfill a certain number of orders anyway
• Bootstrapped businesses where cash flow matters more than growth metrics
• Mature markets where you've already captured the easy wins and remaining customers are increasingly expensive
In these scenarios, cost control strategies help maintain profitable unit economics even if it means leaving some potential conversions on the table. A furniture retailer with 20% margins and high shipping costs, for instance, might accept 30% less volume to ensure every sale remains profitable rather than growing revenue at the expense of the bottom line.
For Consistency
Highest Volume is, by nature, volatile. There will always be good days and bad days in the auction. Using cost controls can provide some much-needed stability to the CPA or ROAS in an account. Rather than CPA fluctuating daily, when using cost controls you can see spend as the fluctuating variable, but a more stable and consistent CPA/ROAS.
When Testing Large Volumes of Creative
Here's a use case many advertisers overlook: cost controls can be invaluable during high-volume creative testing. When you're launching dozens or hundreds of ad variations simultaneously, Highest Volume bidding can quickly allow costs to spiral out of control as Meta's algorithm attempts to learn across so many variables.
For example, an apparel brand testing 50 different creative combinations might use a Cost Cap at their break-even CPA during the testing phase. This ensures they don't risk profitability during this test period. Once they identify the top 5-10 performers, they may then switch those to Highest Volume, or use the following strategy to scale.
For Scale With Proven Creatives
In the above example, we looked at using a cost control during testing and then moving to highest volume for scaling. However, one of our favorite ways to use cost controls is to go the opposite direction. We will often take proven creatives that are performing well in Highest Volume campaigns and put them in a manual bid campaign at a considerably higher budget, but with a strict cost control on it. This can be a very effective way to get significant scale from specific, proven ads without the volatility and risk that come with scaling in Highest Volume campaigns. And, since we generally recommend scaling campaigns gradually, this can also be a way to achieve a significant (potentially short term) budget increase to leverage demand.
When doing this, however - and especially if setting budgets considerably higher than normal - we do recommend using Rules in Ads Manager to protect against overspending with poor results. Some recommendations include a rule that says "If campaign X spends at least $Y with a CPA over $Z (or a ROAS under $Z if using Target ROAS) turn off the campaign." This additional layer of protection can guard against an unintended overspend.
Which Cost Control To Use?
Once you've determined that a cost control is actually going to be helpful, choosing between Bid Cap, Cost Cap, and Target ROAS depends on your specific situation and goals.
Use Bid Cap When:
• You have extremely tight margins and cannot afford any conversion above a specific cost
• Testing new creative or products where you want maximum protection against overspending
• Volume is less important than maintaining strict unit economics
Use Cost Cap When:
• You want to maintain a profitable average CPA while still allowing the algorithm some flexibility
• Scaling proven campaigns where you know your target metrics
• You need more volume than Bid Cap allows but still require cost predictability
• Managing campaigns with consistent margins across products
Use Target ROAS When:
• You sell products with widely varying price points or margins
• Revenue maximization is more important than volume
• Running campaigns for higher AOV products where the focus is on value, not just conversions
And, keep in mind, these aren't necessarily mutually exclusive. In fact, many advertisers who use cost controls end up using a mix of at least two, and sometimes all three. Particularly if one of them is Target ROAS - as it uses Maximum Value bidding it's less likely to overlap with the other controls, which require use of Maximum Volume bidding.
How to Set Your Cost Control
There's a popular misconception that using cost controls creates a "set it and forget it" condition in Ads Manager…that you set a cap or target and then just let Meta do its thing. If you have an absolute, drop-dead CPA target you can't go above (or ROAS target you can't go below) then sure, setting your cap or target at or a little below that number and then leaving it alone will help you achieve that goal, but perhaps - even likely - at the expense of any kind of volume. While less volume is often the trade off when using cost controls, there are still ways to squeeze additional volume out of your controls. This is done by constantly adjusting your cap.
We will typically start at or just below our desired CPA or ROAS target and see how much of the budget Meta will spend. Most likely it won't be very much. We will then gradually adjust the bid to try to increase scale. Ideally with some testing and iteration we'll find a bid that, while it may not provide the same scale as Highest Volume, will still provide an acceptable amount of scale while preserving our desired CPA/ROAS.
There's no set number where this will land. It takes manual oversight to get it right. And, it can be a moving target. Changing auction dynamics, creative fatigue and changes, and offer and landing page changes can change the equation. If we find that we aren't getting the same level of scale we previously were, we move the bid to try to get more. On the opposite side, if our CPA or ROAS takes a turn for the worse we will adjust the bid the other way to try to protect profitability.
Conclusion: Cost Controls Are Tools, Not Solutions
If there's one thing to take away from this guide, it's this: Meta's cost controls aren't performance enhancers—they're specialized tools for specific business requirements. The proliferation of "advanced" strategies featuring complex bidding setups has led many advertisers to believe that sophistication equals success. In reality, the opposite is often true. Highest Volume bidding remains the most powerful option for the majority of advertisers because it gives Meta's increasingly sophisticated algorithm the freedom to do what it does best.
Cost controls have their place, absolutely. When margins are razor-thin, when testing needs boundaries, when consistency matters more than scale, or when you need to rapidly deploy proven creative at higher budgets—these are the moments when Bid Caps, Cost Caps, and Target ROAS earn their keep.
Start with Highest Volume. Let it run. Establish your baseline. If specific business needs arise that Highest Volume can't address introduce the appropriate cost control. Monitor it closely and adjust it regularly.
And remember, your creative, offer, and landing page will always matter more than your bidding strategy. Focus your energy there first. When you do need cost controls, use them strategically and intentionally. And when you don't need them? Let the algorithm run free.