How you pay your agency matters less than two things: can you see what you’re paying, and does it scale fairly? The percentage model earned a bad name because of how it’s usually run, a flat rate with undisclosed markup layered on top. Strip out the hiding and let the rate decline as you grow, and a percentage becomes the model that matches the work to your account.
This is the one comparison where we have a clear, public position, because it’s how we price. We charge a transparent percentage of your ad spend, billed like tax brackets so the rate drops as you scale, with a monthly floor and zero markup on your media. You can do the math yourself.
So this page isn’t “percentage bad, flat good.” It’s the honest version: here’s what went wrong with agency pricing, why a flat fee is a blunt fix, and how a transparent, declining percentage solves the real problem. Here’s the case.
The percentage was never the crime. The hiding is.
The reason percentage-of-spend gets a bad name isn’t the percentage. It’s the margin agencies bury inside the spend, where you can’t see it. The ANA’s landmark transparency investigation documented principal-media markups of 30% to 90%, and undisclosed ad-tech markups of 200% to 250%, layered into the media itself.
It isn’t just one study. A forensic audit of the programmatic supply chain by ISBA and PwC found that only about half of advertiser spend reached publishers, and 15% of it was an “unknown delta” that no party could even account for. The enemy is opacity, not the existence of a fee.
A fee you can see and verify is a different animal from margin hidden inside your media.
Margin hidden inside media spend
A flat fee is honest. It’s also blind to your account.
A flat fee removes the markup incentive, and that’s genuinely good. But it’s a blunt instrument. The same fixed number overcharges a small advertiser and under-resources a growing one, because the work behind paid media scales with the account: more budget means more campaigns, more creative, more to watch.
It also detaches what the agency earns from the thing that needs daily attention, your spend and its efficiency. Honest, yes. But “honest and blunt” isn’t the same as “aligned.”
A flat fee is honest. It just can’t tell a $2,000 budget from a $200,000 one.
For automated media, the pros already pay on spend.
Percentage pricing isn’t a relic. In the ANA’s compensation research, 40% of advertisers tie their programmatic pay to spend, 28% on a fixed rate and 12% on a sliding scale, making it the single most common way the most automated media is bought.
Advertisers choose it for a reason: it flexes with their budget through the year without renegotiating scope every season. And that 12% sliding scale is the tell, it’s a declining percentage, the exact structure that fixes the model’s one real weakness.
Percentage is the leading model for automated buying
A rate that falls as you scale.
The one fair criticism of percentage pricing is that a flat rate balloons as your budget grows, you pay more for the same work. The fix is a marginal rate, billed like income-tax brackets: each slice of spend is charged at its own rate, and the rate steps down as you grow.
That’s how we price. Your effective management rate starts at 15% on the first $10,000 a month and falls toward 3% as you scale, so scaling up is never a windfall for us. A monthly floor keeps small accounts properly managed instead of overcharged.
Your rate drops as your spend grows
The management is the product, and it compounds.
A management fee is for management, and active management is measurable. Google’s own data shows advertisers who raised their account-level Optimization Score by 10 points saw a median 14% increase in conversions. Accounts drift when they’re left alone; Google says keywords and bids left unchanged go stale as conditions move.
And the job gets harder every year: US digital ad revenue hit a record $258.6 billion in 2024, up nearly 15% in a single year, with more advertisers competing for the same auctions. Paid media is not set-and-forget, which is exactly why the fee should track the account it manages, transparently, and decline as that account grows.
What continuous optimization correlates with
If you ask any agency media buyer to choose between a 75% margin and a 20% margin, guess what’s going to happen?
Richard Plansky, lead investigator on the ANA media-transparency report
Advertisers and their agencies are lacking full disclosure as the cornerstone principle of their media management practices.
Bob Liodice, President and CEO, Association of National Advertisers
Which paid-media pricing fits you? Take 30 seconds.
A few taps and you’ll get a straight read on the structure that fits your budget, with the one thing to insist on either way.
Roughly how much do you spend on ads each month?
A transparent percentage that falls as you scale.
MoonSauce prices paid media as a transparent percentage of your spend, billed like income-tax brackets so your effective rate drops as you grow, from 15% on the first $10,000 a month down toward 3% at scale, with a monthly floor so small accounts are still managed properly. Scaling up never hands us a windfall; it lowers your rate.
And there’s zero markup or rebate on your media. You pay the platforms directly, the management fee is the only fee, and you can run the exact numbers yourself on our pricing page. The percentage scales the work to your account, the declining rate keeps it fair, and the transparency means nothing is hidden.
Frequently asked
Isn’t percentage-of-spend a conflict of interest?
Why not just charge a flat fee?
What’s wrong with most agency pricing, then?
Does my rate really go down as I scale?
How does MoonSauce charge for paid media?
Every figure on this page comes from a primary platform, an independent study, or a named industry expert. No competing-agency stats, no made-up numbers.
- ANA / K2 Intelligence: media transparency study (markups and rebates), 2016
- ISBA / PwC / AOP: Programmatic Supply Chain Transparency Study (15% unknown delta), 2020
- ANA: Media Agency Compensation Practices (fee vs commission, sliding scale), 2019
- Google Ads: campaign recommendations and Optimization Score (+14% median conversions)
- IAB / PwC: US digital ad revenue 2024 ($258.6B record, +14.9%)
- ANA / K2 transparency report coverage (via AdExchanger)
- Digiday: revisiting the K2 report on media-agency practices
- MoonSauce pricing (transparent declining brackets, live calculator)
