Short answer
Hire an agency if your problem is strategy. Buy software if your problem is that nobody is watching the account. An agency ($1,500–$10,000/mo, or 10–20% of ad spend) brings judgment, creative, and someone accountable. Software ($50–$1,000/mo) brings daily execution that happens whether or not anyone logs in.
Most businesses under ~$10k/mo in spend are paying agency prices for work software does better. Most businesses over ~$50k/mo need both — and should stop paying a percentage of spend for either.
They’re not competing for the same job
The comparison gets framed as “human vs. machine,” which is the wrong frame and leads people to the wrong answer. Ad management is two jobs wearing one coat.
- The thinking. Who to target. What to say. What the offer should be. Whether this channel is even right for you. What a customer is worth and what you can afford to pay for one. This is judgment, and software is nowhere close.
- The grind. Nudging bids. Pausing the ad that spent $60 and produced nothing. Shifting budget from the dying campaign to the working one. Doing it every single day — which is precisely why humans don’t.
Agencies sell you both and charge for both. Software does one of them, far better and far cheaper. The question isn’t which is better. It’s which job you’re actually buying.
Run the math
Management is only worth paying for if it improves results by more than it costs. So work backwards from that.
Spend: $10,000/month.
Agency at 15%: $1,500/mo. Your true cost of advertising is $11,500. For that fee to pay for itself, they have to make your $10,000 perform at least 15% better than you would alone. Achievable for a good agency. Impossible for a bad one.
Software at $499: Your true cost is $10,499. The bar drops to roughly a 5% improvement — but you’re still making the strategic calls yourself.
Two conclusions fall straight out of that arithmetic:
- At low spend, agency fees rarely make sense. At $3,000/mo of spend, a $1,500 retainer means a third of your total budget goes to management. The improvement needed to justify it is enormous.
- At high spend, the fee stops being the point. At $50,000/mo, the gap between a great strategist and a mediocre one is worth vastly more than the gap between a $5,000 and a $7,000 retainer. Optimize for quality, not price.
The incentive problem
Percentage-of-spend pricing — the most common agency model — means your agency’s revenue rises when your budget rises, whether or not the extra spend worked.
Most agencies are honest and will tell you to hold steady when you should hold steady. But the pressure is structurally there, and the person best placed to say “don’t scale this month” is the person who gets paid less for saying it. Notice how often the recommendation happens to be “scale up.”
The same question applies to software, incidentally. Ask any tool whether its fee scales with your spend — and whether it can raise your budget on its own. Cesara charges flat tiers and cannot raise your budget without your approval, which are two different ways of saying the same thing: nobody here gets paid more for telling you to spend more.
A cheat sheet
- Under $5k/mo spend: software, almost always. Agency fees eat too much of a small budget.
- $5k–$30k/mo: software for the grind; a freelancer or consultant for strategy and creative if you need it. This is where the hybrid wins.
- $30k+/mo: you probably want both — but on a flat retainer, not a percentage. At that scale the percentage is real money for no extra work.
- You don’t know your numbers: hire a human first. No software can optimize toward a target you haven’t set.
The full pricing breakdown, with sources, is in how much ad management costs per month.
Pay for the thinking. Automate the grind.
Reserve founding-member pricing — no card, nothing charged today.