Sooner or later every growing brand asks the same question: do we hire someone to run paid media in-house, or bring in an agency? The honest answer is that it depends on your spend, your stage and how central paid is to the business. Here is how to think about it without the usual bias in either direction.
The cost question, done properly
In-house feels cheaper because you compare one salary to an agency retainer. That comparison is wrong. A capable in-house setup is not one person; it is a media buyer, plus creative to feed them, plus someone who can be trusted with measurement. Add salaries, benefits, tools, and three to six months of ramp before they are productive, and the real number climbs fast. Below roughly US$100k a month in ad spend, an agency is usually the cheaper route to senior expertise, not the more expensive one. Above that, the maths starts to favour building a team. For the full breakdown of agency pricing, see what a performance marketing agency costs.
Speed and control: the case for in-house
The strongest argument for in-house is proximity. Someone in the building lives your brand, sits in the room, and can change a campaign the moment the plan changes. There is no back-and-forth, no ticket queue, no context lost in translation. If paid media is the core engine of the business and you are moving fast, that control is worth a lot. In-house also keeps the knowledge inside the company, where it compounds.
Expertise and perspective: the case for an agency
The strongest argument for an agency is range. A good agency runs many accounts across many industries, so it has seen the pattern you are hitting a dozen times and knows which fix works. It carries specialists, media, creative, measurement, CRO, rather than asking one hire to be great at all of them. And it brings an outside perspective that an internal team, staring at the same account every day, tends to lose. Depth across the channels that actually drive your revenue is the thing to buy, whether that is Meta, Google or both.
The risk nobody prices in
In-house carries key-person risk. When one or two people hold all the knowledge, a resignation can cost you months. It also carries perspective risk: an internal team only ever sees your account. Agencies carry their own risks, the junior-on-the-account bait and switch, misaligned incentives, and reporting built on flattering platform metrics, which is exactly why how you choose the agency matters as much as the decision to use one. The common thread under both is measurement: whichever route you take, if the numbers are not trustworthy, neither will save you.
When each option wins
Choose in-house when: paid is core to the business, spend is high and stable, you need maximum speed and control, and you can genuinely hire and keep senior talent plus the support around them.
Choose an agency when: you want senior expertise now without a long hire, you are spending under six figures a month, you need multiple channels covered, or your measurement and structure need fixing before anything else can work.
The option most brands should consider first
For a lot of companies the best answer is neither pure model but a hybrid. Keep strategy, measurement and specialist channel work with an agency, and let an in-house marketer own brand, coordination and the day-to-day. You get senior expertise and outside perspective without carrying the full cost or the single-point-of-failure risk of a complete in-house team. It is also the natural on-ramp: many brands use an agency to build the measurement and structure first, then bring execution in-house once the machine is clean and the case for a team is obvious.
How to decide in one step
Before you commit to either path, get an outside read on where your account actually stands. A free paid media leak audit shows you what is working, what is leaking, and what a senior operator would change, thirty minutes, no obligation. Whether you end up building in-house or hiring an agency, you will make the decision from facts about your own account rather than a generic rule of thumb.