How to Choose and Manage a Marketing Agency as a Startup

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By Saroj Jha · October 4, 2026 · 10 min read

Hire an agency for specialist work you need part-time, once your positioning is clear and you know which channel you want to grow. Keep strategy in-house, pay a fee for a defined scope, and judge the agency on pipeline, not clicks.

Agencies can give a startup skills it could not hire full-time. They can also absorb budget for months without moving the numbers. The difference is mostly in how the founder chooses, briefs and manages them.

This post works through five steps, with the research that exists. Most of that research comes from large advertisers, so I say where it applies to startups and where it may not. I flag where I am giving my own view.

Running case: Example Co. Fictional

Example Co. is a seed-stage B2B SaaS startup whose software automates the month-end close for finance teams at companies with 50 to 500 employees. The controller is the champion and daily user; the CFO or VP Finance signs; IT reviews security. The team of eight includes two founders and one account executive, and the goal is 30 new customers in the next 12 months. The message is agreed: “Close the books in days, not weeks, without adding headcount.” Founder-led outreach works, but the founders have no time to run LinkedIn ads well, and they are wondering whether an agency should. Example Co., its agencies and all numbers are illustrative.

Step 1: Decide whether an agency is the right fit

Large advertisers now build in-house and buy from agencies at the same time. In the Association of National Advertisers’ 2023 survey of 162 members, 82% had an in-house agency, up from 42% in 2008, and 92% also worked with external agencies; on average, 61% of the work was done in-house^[1]. ANA members are mostly large advertisers, but the pattern of keeping core work inside and buying specialist work outside suits startups too.

AI tools are changing the balance. In Gartner’s 2025 survey of 402 CMOs, most at companies with more than $1 billion in revenue, 22% said generative AI had reduced their reliance on external agencies for creativity and strategy, and 39% planned to cut agency budgets^[4].

In my view, a startup is ready for an agency when three things are true: your positioning and ideal customer are clear, you know which channel you want to grow, and someone on your side has the time to brief and manage the agency. An agency cannot find your product-market fit or your positioning for you; it can execute and scale what you already know.

Example Co., step 1 Fictional

The founders walk through the three questions. Positioning is clear: the message and the ideal customer are agreed. Positioning, customer interviews and content stay with the founders, because that is how Example Co. wins. Designing a first set of ads is a defined, one-off task, so it goes to a freelancer on a project fee. Running LinkedIn ads week after week needs depth and tools the team lacks, so that is the job for a specialist agency.

Do this

List the marketing work you need for the next six months and put each item through the three questions. Only the items that end at “specialist agency” belong in an agency brief. My post on your first marketing hire compares the hiring route, and the Marketing Leadership Cost Comparator puts numbers on the options.

Free tool

Put an agency against a hire on your own numbers

The free Marketing Leadership Cost Comparator sets a full-time hire, a fractional leader and an agency side by side: fully loaded cost, cost per productive month and the break-even month.

Step 2: Shortlist on evidence, then run a paid trial

Choose on evidence that matches your situation:

• Relevant work. Similar stage, similar buyer (B2B or B2C), similar channel. Ask for results they can explain, not just logos.
• The actual team. Meet the people who will do your work, not only the ones who pitch.
• How they measure. Ask how they would judge success for you and how they report. Look for pipeline and revenue, not only clicks.
• References. Speak to one current and one former client of a similar size.
• Fit and trust. In a 2024 survey of 173 people at large US advertisers and their agencies, 56% named trust as the most important factor in the relationship, and 90% of clients said value and long-term return outweighed cost in choosing an agency^[5].

Don’t ask for free strategy. The 4As, the US agencies’ trade association, recommends that agencies keep ownership of the ideas and plans they create in a pitch “unless the client is prepared to pay the agency fairly for the rights”^[6]. Pitches are also expensive for both sides. Instead, pay your top one or two choices for a small, defined trial project and choose on the result.

Example Co., step 2 Fictional

The founders collect eight names from peers and partners. Three can show results with B2B SaaS companies and name the people who would run the account. Two pass their reference calls. Example Co. pays both, Agency A and Agency B, $3,000 each for a four-week trial on the same small LinkedIn budget, with the same brief. Agency B produces more qualified demos and clearer reporting, so it wins. The agencies and numbers are fictional.

Do this

Write down your five selection criteria before the first agency call, and budget for a paid trial with two finalists.

Step 3: Agree how you will pay

Mostly by fee for a defined scope. In the ANA’s 2022 agency compensation study, the latest with public results (101 marketers, 336 agency relationships), 82% of advertisers used fee-based models, up from 68% in 2016, and smaller advertisers were especially likely to use fees based on the agency’s time (76%). Use of performance incentives fell to 41%, from 48% in 2016 and 61% in 2013^[2].

Be careful with pay-for-performance. A 2025 study of how agencies respond to incentives in creative work proposes a model in which “pay-for-performance only works when trust is low already”^[7]. In my view, tying fees to results the agency doesn’t control, such as your sales team’s close rate, invites disputes. Figure 4 shows where I draw the line.

Example Co., step 3 Fictional

Example Co. agrees a monthly retainer of $4,000 for LinkedIn ads management. Media spend of $8,000 a month sits on a separate line of the quote, and Example Co. pays it straight to LinkedIn from its own ad account. There is no performance bonus in the first six months; the founders will reconsider once both sides trust the numbers. All figures are fictional.

Do this

Ask every agency to split its quote into fee and media spend. If you cannot see the two separately, you cannot judge either.

Step 4: Write a one-page brief

On one or two pages, covering:

1. The business goal in numbers (for example, qualified pipeline per quarter).
2. The customer: who they are, what they need, what they use today.
3. Your positioning and message, and what you will not say.
4. The scope: channels, deliverables, what the agency owns and what you own.
5. Budget and timing, including media spend separately from fees.
6. How success will be measured and how often you will review it.

A clear brief is, in my view, the cheapest way to improve agency results. For content work, the Content Brief Builder turns a target search query into a writer-ready brief.

Example Co., step 4 Fictional

Example Co.’s brief fits on one page (Figure 5). The line that matters most is the goal: 12 qualified demos a month from LinkedIn ads by the end of the second quarter, as one part of the plan for 30 new customers in 12 months. Every other line explains how the agency can help reach it. Fictional numbers.

Do this

Write the brief before you meet agencies, not after. The best ones will ask better questions of a clear brief.

Step 5: Measure, review and keep the exit easy

Manage with a small set of measures and a regular review:

• Three to five measures, agreed at the start, tied to the business goal: qualified pipeline, cost per qualified opportunity, conversion rates, and one or two leading indicators.
• A monthly report and a quarterly review covering what worked, what didn’t and what changes next.
• Access to everything. Ad accounts, analytics and creative files in your company’s name, with the agency as a user. LinkedIn, for one, recommends that the business that pays the bill owns the ad account, and moves ownership later only through its support team if both sides agree^[8].

Give the agency room to do its job. A study of client–agency collaboration found that “clients often had difficulty ceding control and trusting an outside agency”, which limits what the agency can contribute^[12]. Stability helps too: an ANA and 4As study found agency relationships without mandatory review periods lasted longer, about 8.1 years, than those with frequent reviews, as low as 3.8 years^[3]. Review performance often; don’t re-pitch the account often.

The contract should cover scope and deliverables; fees and how extra work is priced; who owns the work, the data and the ad accounts; notice period and handover; confidentiality; and how media spend is billed. Make sure you can leave with your accounts, data and files intact. Two points need care. In the US, work an outside firm makes for you is usually not yours by default: unless it falls into a few narrow categories and both sides sign a work-made-for-hire agreement^[13], you need a written transfer of copyright signed by the agency^[14]. And you stay answerable for what the agency does in your name: the FTC says handing part of your promotion to an outside company “doesn’t relieve you of responsibility under the FTC Act”^[15]. This is general information, not legal advice.

What an agency group’s own filing shows

There is no public filing from a startup about how it managed its agency, so I have looked at the other side. The largest agency groups are listed companies and must describe their risks to investors. Omnicom’s annual report for fiscal 2025 states: “Clients generally are able to reduce or cancel current or future spending on marketing and communications services at any time on short notice for any reason.” It also states: “From time to time, clients may put their marketing and communications business up for competitive review”^[16].

These are what the filing tells investors, not an account of how Omnicom manages any client relationship, and Omnicom serves mostly large marketers rather than startups: its 100 largest clients brought in about 54% of its 2025 revenue^[16]. In my view, the two sentences still carry two lessons for a founder. First, short notice is normal in this industry, so ask for it and keep your accounts in your own name so leaving is easy. Second, reviews are normal too, but the ANA and 4As tenure data above suggest that frequent re-pitching shortens relationships; use the quarterly review, not a new pitch, as your main tool.

Example Co., step 5 Fictional

Example Co. agrees four measures with Agency B: qualified demos per month (target 12), cost per qualified opportunity (target under $2,000), demo-to-deal rate, and, as a leading indicator, the share of ad clicks from finance job titles. The agency sends a report on the fifth working day of each month; both founders join a quarterly review. The contract runs six months, then continues with 30 days’ notice, and every ad account sits in Example Co.’s name. All targets and terms are fictional.

Do this

Before you sign, check four things in the contract: the notice period, who owns the ad accounts and data, a signed transfer of copyright in the work, and how media spend is billed.

What changes by stage?

• Pre-seed — Freelancers for specific tasks. Keep strategy with the founders.
• Seed — One specialist agency for the channel you are scaling, managed by a founder, marketer or fractional leader.
• Series A–B — Agencies for specialist channels alongside an in-house team that owns strategy, content and data.

What mistakes should I avoid?

• Hiring an agency to find your positioning. That work needs to sit with you.
• Choosing on the pitch team. Meet the people who will do the work.
• Asking for free strategy. Pay for a small trial instead.
• Measuring clicks. Agree measures tied to pipeline.
• Ad accounts in the agency’s name. You can lose the account and its history when you leave.
• Paying on results the agency can’t control. It creates disputes, not performance.
• Re-pitching instead of reviewing. Fix problems in the quarterly review first.