Agency red flags: how to spot a marketing agency that will cost you growth

Guaranteed ROAS promises, reports full of vanity metrics, no opinion on your creatives and a new account manager every quarter. These are the signs you are talking to the wrong agency.

The four biggest red flags when evaluating a marketing agency are guaranteed ROAS promises, reports full of vanity metrics, the absence of any opinion on your creatives, and an account manager who changes every few months. Each of these signals points to the same underlying problem: an agency built to win clients rather than grow them. In this article we walk through them one by one, so you can spot them in the very first call.

Why is a ROAS guarantee a red flag?

Nobody can guarantee ROAS. Your results depend on your product, your margins, your offer, your website, your market and the quality of your creatives. An agency that promises a number in the first conversation has seen none of those factors, which means it makes that same promise to everyone. That tells you something important: the guarantee is a sales tool, not an assessment.

There is a nastier mechanism underneath as well. A guaranteed ROAS is almost always achievable by simply staying small. Run nothing but retargeting against people who were going to buy anyway and you will report a beautiful ROAS on revenue that barely grows. The promise gets kept while your business stands still. For B2C companies trying to move from €15-20K per month toward €150-200K, that is exactly the wrong incentive.

How do you recognize vanity reporting?

Open the last report an agency sent you and ask yourself one question: can I tell from this how many net-new customers and how much revenue the campaigns produced? If the answer is no, you are looking at vanity reporting. Impressions, reach, clicks, CTR and engagement are all useful diagnostic metrics, but they are not results. They tell you how busy the agency has been, not what it has delivered.

• A healthy report starts with spend, revenue, net-new customers and the relationship between them.
• Diagnostic metrics like hook rate, CTR and frequency belong in there too, but as explanation, never as conclusion.
• Every report should include a section covering what was tested, what the learning was and what happens next week.

Watch the basis of comparison as well. An agency that highlights a different metric every month is simply picking whichever number happens to look good. A partner who takes you seriously reports the same core KPIs every week, including the weeks when things go wrong.

Why should an agency have an opinion on your creatives?

Creative is the biggest lever in paid social. Targeting is largely automated, campaign structure can be copied in an afternoon, but the question of which concept makes a stranger stop scrolling and buy is where the difference gets made. An agency that only talks about budgets, bid strategies and campaign settings is managing your account, not growing it.

So in the first call, ask what the agency thinks of your current ads. A good partner has looked at them and formed a view: which angle is going unused, where the hooks are too slow, what proof is sitting in your reviews that nobody has touched yet. We have produced more than 15,000 creatives over the past years, and that volume taught us one thing above all: without a strong creative vision, media buying is just the optimization of mediocrity.

An agency that guarantees your ROAS before seeing your account is mostly guaranteeing that it does not understand your business.

What is account manager roulette?

You may know the pattern. For the first few months a sharp strategist sits at the table, then your account is quietly handed to a junior, and every six months you get to explain your brand, your customer and your testing history all over again. Every handover burns knowledge, momentum and learnings that were never documented anywhere. You keep paying the same fee, but each time you get someone who has to start from zero.

Ask explicitly, before signing, who will work on your account day to day, how long that person typically stays on it and how learnings are documented. An agency that gets evasive here has already given you the answer.

How do you recognize a good partner?

Flip the test around: pay less attention to what an agency promises and more to what it asks. A serious partner wants to know your margins, your repeat customer ratio, your best and worst products, what you have already tested and why you left your previous partner. It also dares to say no: to margins that are too thin, to a website that is not ready, to expectations that are not realistic. That feels less pleasant in a sales call than a guarantee does, but it is exactly the behavior you want once the work starts.

Conclusion

Spotting red flags comes down to a simple pattern: guarantees, vague reporting, no creative opinion and a rotating cast of faces all point to an agency that sells instead of builds. The alternative is a partner who starts with strategy: which angles, which concepts and which proof your brand needs to turn strangers into customers, and who manages toward that every single week. That is how we work, with creative strategy as the foundation under everything we run for brands. Curious what that looks like for your brand? Book a call and we will gladly take a look with you.