Finding a good paid ads agency can feel like a proper nightmare. You're bombarded with promises of 'skyrocketing your ROI' and 'guaranteed results', but you know deep down that most of it is just noise. You've probably heard horror stories from other business owners who've been burned, left with a lighter bank account and not much else to show for it. It's a high-stakes decision, and getting it wrong can set you back months, not to mention a lot of money.
But here’s the thing. There is a way to see through the sales pitches and find a partner that can actually help you grow. It's not about finding the agency with the slickest website or the most confident salesperson. It's about knowing what questions to ask, what to look for in their work, and how to spot the red flags they hope you'll miss. This isn't just a checklist; it's a completely different way of thinking about how you hire an agency. It's about turning their sales process into your interview process.
Their Case Studies Tell a Story, But Are You Reading it Right?
Every agency website has a 'Case Studies' or 'Our Work' page. They're usually filled with flashy logos and big, impressive numbers. It's easy to look at a headline like "1000% Return On Ad Spend" and think, "That's what I want!" But hold on. A case study isn't proof of competence; it's a marketing document designed to sell you. Your job is to look past the headline and dissect what's really being said, and more importantly, what isn't.
First off, is it even relevant to you? I've seen agencies that specialise in local services showcasing a huge eCommerce win. It's impressive, sure, but running Google Ads for an electrician is a world away from selling subscription boxes on Meta. You need to see evidence they understand your world. When we talk to a potential SaaS client, we don't just show them our best results, we show them results like the 5082 Software Trials at $7 cost per trial we achieved for a software company, or the campaign where we reduced a medical job matching SaaS client's cost per user from £100 down to £7. It's specific. It shows we've been in their trenches before.
Look at the platforms they used. Your enquiry mentioned needing an 'Instagram Ads agency'. If an agency only shows you case studies from Google Search or LinkedIn, that's a massive red flag. They might be brilliant at search ads, but that doesn't mean they know the first thing about building a high-performing campaign on Meta. You need to see proof of expertise on the specific platforms that matter for your business.
Then you've got to scrutinise the results themselves. What do the numbers actually mean? I remember one campaign where we achieved 10 Million Views for a luxury brand launch, and it was incredible, but if you're a small business trying to sell a product, views don't pay the bills. You need to see case studies that talk about the metrics that matter to a business owner: leads, cost per lead (CPL), sales, and Return On Ad Spend (ROAS). If all they talk about is clicks, impressions, and reach, they're either hiding poor performance or they don't know how to track what's actually important. They're measuring activity, not outcomes.
Here’s a contrarian thought for you: a case study that shows a bit of a struggle can be more revealing than a perfect success story. One that details how they started with a high CPA, then tested creatives, refined targeting, and successfully brought it down, shows me they can problem-solve. Anyone can get lucky with one campaign. A great agency knows how to diagnose a problem and fix it. That's the skill you're paying for.
Think of it like this. You're not just looking for a highlight reel. You're looking for a documented history of solving problems similar to yours. Don't be dazzled by logos; be critical of the story they're telling you.
Here's a quick way to spot the difference between a useful case study and a useless one:
| What a WEAK Case Study Shows | What a STRONG Case Study Shows |
|---|---|
| Vague platitudes: "We increased their online presence." | Specific metrics: "Generated £107k in revenue at 618% ROAS for a prize draws client." |
| Vanity metrics: "Achieved 2 million impressions." | Business metrics: "Acquired 4,622 B2B software registrations at $2.38 each." |
| Irrelevant industry: "Helped a local cafe." (When you're a SaaS company). | Niche relevance: "Drove 1535 trials for a B2B SaaS product on Meta Ads." |
| No mention of platforms: "Used digital advertising." | Platform specific: "Reduced CPL on LinkedIn Ads by 84% for an environmental controls client." |
If their case studies look more like the left column than the right, be very, very careful.
What Should I Ask Them on the 'Free Consultation'?
So you've reviewed their case studies and decided to book that "free consultation" or "strategy session". Most business owners treat this as a chance for the agency to pitch them. That's a mistake. This is your chance to interview them. You hold the power here. Your goal isn't to be sold to; it's to extract as much information as possible about their expertise and process.
Don't let them control the conversation with a generic slide deck about their agency's history and values. Interrupt. Ask questions. Make them think on their feet. A good agency will welcome this; a bad one will get flustered. We offer a free initial consultation where we review a potential client's strategy and account right there with them. It's not a pitch. It's a working session. It gives them a real taste of the expertise they'd be getting. That's the standard you should look for.
The single biggest red flag is an agency that promises you results. "We'll get you a 5x ROAS in the first month!" sounds great, but it's a lie. Tbh in paid advertising, you can't really promise anything. There are too many variables: your offer, your website's conversion rate, market competition, the mood of the algorithm that day. A true expert knows this. They'll talk in terms of process, testing methodology, and establishing benchmarks. They'll sound cautious and realistic, not like a used car salesman. If it sounds too good to be true, it absolutely is.
You need to go into this call armed with your own numbers. The most powerful question you can ask is one that forces them to apply their expertise to your specific situation. This is where you can use the concept of Customer Lifetime Value (LTV).
Let's do a quick calculation. It's simpler than it sounds.
- Average Revenue Per Account (ARPA): What's a customer worth to you each month? Let's say it's £300.
- Gross Margin %: What's your profit on that? Let's say it's 70%.
- Monthly Churn Rate: What percentage of customers do you lose each month? Let's say 5%.
The calculation is: LTV = (ARPA * Gross Margin %) / Monthly Churn Rate
So: LTV = (£300 * 0.70) / 0.05 = £210 / 0.05 = £4,200.
Each customer is worth £4,200 in gross margin to you. Now you can go into that consultation and ask: "My LTV is around £4,200. I'm aiming for a 3:1 LTV to Customer Acquisition Cost ratio. That means I can afford to spend up to £1,400 to acquire a customer. What's your initial strategy to hit a CPA below that number?"
This single question changes everything. It shows you know your numbers. It forces them to think strategically, not just talk about clicks. Their answer will tell you everything you need to know. Do they start talking about audience testing, creative angles, and landing page optimisation? Or do they give you a vague, non-commital answer? One is an expert, the other is a chancer.
Key Questions to Ask on the Initial Call:
Forget "Tell me about your agency." Ask these instead:
- -> Based on my business model and target audience, which ad platform would you prioritise first and why? (Tests their strategic thinking).
- -> You saw my website. What's the first thing you'd change on my landing page to improve conversion rates? (Tests their understanding of the full funnel).
- -> What does your testing process look like? How do you decide when to kill an ad or an audience? (Tests their methodology).
- -> My LTV is [your LTV]. What CPA/ROAS would you consider a 'win' in the first 90 days? (Tests their financial acumen).
- -> Tell me about a campaign you ran that failed. What went wrong and what did you learn? (Tests their honesty and ability to learn).
An agency worth hiring will have solid, confident answers to all of these. An agency you should run from will try to dodge them.
Is Their 'Proprietary Funnel' Just a Template?
You'll hear this a lot. Agencies love to talk about their "proprietary funnel" or their "proven system". It sounds impressive, like they've cracked a code that no one else has. The reality is often less exciting. More often than not, it's just a rigid, one-size-fits-all template that they apply to every client, regardless of their niche, audience, or goals.
This is a huge problem. Selling a high-ticket B2B service to a CFO is fundamentally different from selling a £20 t-shirt to a teenager on Instagram. A templated approach might work for one (if they're lucky), but it will almost certainly fail for the other. A great agency doesn't have a magic funnel; they have a flexible framework and a deep understanding of strategy. They build the funnel around your business, not the other way around.
The first step a good agency takes is to obsess over your customer. Not just their demographics – "females, 25-34, live in London" – but their pains, their fears, their goals. Your ideal customer isn't a demographic; they're in a specific problem state. A Head of Sales isn't just a job title; he's a guy who's stressed because his team is missing quota and he needs better leads, now. An agency that doesn't spend the first call trying to understand this 'nightmare' in detail has no business taking your money.
Once they understand the customer, then they can talk about the right platforms and tactics.
-> Is your customer actively searching for a solution to their problem right now? If you're a plumber, the answer is yes. People don't browse Facebook for emergency pipe repairs. They go to Google. So Google Search ads are your best bet, targeting keywords like "emergency electrician near me".
-> Are you trying to reach specific decision-makers in certain industries? A template based on Facebook interests won't work. You need the powerful B2B targeting of LinkedIn Ads. I remember one campaign where we achieved CPLs as low as $22 for B2B decision makers for a software client on LinkedIn Ads, something that would be near impossible on other platforms.
-> Are you selling a visual product or something that people don't know they need yet? This is where social media ads on platforms like Meta (Facebook/Instagram) shine. You can build awareness and create demand.
A good agency thinks like this. They match the channel to the customer. A bad agency just plugs you into their pre-built 'Meta Ads Funnel' because it's what they know how to do.
The structure they propose should also make sense for your sales cycle. For eCommerce, a common structure is ToFu/MoFu/BoFu (Top, Middle, Bottom of Funnel). For B2B, a fixed funnel might not work at all. It's more about lead generation, nurturing, and custom proposals. If they try to sell a B2B client on a complex, multi-step funnel with tripwires and upsells, they likely have more experience with B2C and are trying to force a square peg into a round hole.
Example Funnel Thinking (eCommerce)
This is a framework, not a rigid rule. A good agency adapts it.
| Funnel Stage | Audience | Goal | Typical Tactic |
|---|---|---|---|
| ToFu (Top) | Cold audiences (Interests, Lookalikes of purchasers) | Awareness & Traffic | Engaging video ad showing the product in use. |
| MoFu (Middle) | Website Visitors, Video Viewers (who haven't bought) | Consideration | Carousel ad showing different features or testimonials. |
| BoFu (Bottom) | Added to Cart, Initiated Checkout | Conversion | Dynamic Product Ad with a discount code to close the sale. |
Ask them to walk you through what the funnel would look like for your business. If their answer is vague or sounds exactly like a generic template, you haven't found an expert. You've found a machine operator.
How Do I Know What 'Good' Results Actually Look Like?
This is the million-dollar question, isn't it? Or rather, the million-pound question. You're about to invest thousands, maybe tens of thousands, into advertising. You need to know what a good return on that investment looks like. But there is no single magic number. "Good" is completely relative to your business, your margins, your market, and your goals.
Anyone who tells you "a good CPL is under £20" or "you should aim for a 4x ROAS" without knowing your business inside-out is talking nonsense. For a company selling £5,000 software subscriptions, a £500 CPL could be an absolute bargain. For a company selling £25 t-shirts, a £20 CPL would be a disaster. It's all about context.
This brings us back to the LTV:CAC ratio we talked about earlier. This is your north star. A healthy business typically aims for a ratio of 3:1 or higher, meaning for every £1 you spend to acquire a customer, you get at least £3 back in lifetime value. A good agency understands this and will build their strategy around your numbers, not some arbitrary industry benchmark.
That being said, it's helpful to have some rough ballparks in mind, just to know if you're in the right postcode. Based on the campaigns we've run for hundreds of clients, we've seen some patterns. Remember, these are broad estimates and can vary wildly.
Ballpark Cost Per Result Ranges (Based on Our Experience)
These are for guidance only. Your own results will differ.
| Objective & Market | Typical CPC Range | Typical Conversion Rate | Estimated Cost Per Result |
|---|---|---|---|
| Signups (Leads) - Developed Countries (UK, US, etc.) | £0.50 - £1.50 | 10% - 30% | £1.60 - £15.00 |
| Signups (Leads) - Developing Countries | £0.10 - £0.50 | 10% - 30% | £0.33 - £5.00 |
| eCommerce Sales - Developed Countries | £0.50 - £1.50 | 2% - 5% | £10.00 - £75.00 |
| eCommerce Sales - Developing Countries | £0.10 - £0.50 | 2% - 5% | £2.00 - £25.00 |
So, if you're selling products in the UK and your cost per purchase is £40, you're right in the middle of that typical range. That's not necessarily bad. The real question is, what's your average order value and profit margin? If your AOV is £150 with a 50% margin (£75 profit), then a £40 CPA is brilliant. If your AOV is £50 with a 30% margin (£15 profit), then you're losing money on every sale.
This is the conversation a good agency will have with you. They'll help you understand your numbers and set realistic targets. I remember one home cleaning service client who was getting leads for £5 each, which was fantastic. But I also remember an HVAC client in a super competitive US market where a $60 lead is considered a big win because one closed job is worth thousands. It's all relative.
Don't get fixated on hitting the lowest possible cost per result. Sometimes, paying a bit more gets you a much higher quality lead or customer who spends more over their lifetime. The goal isn't cheapness; it's profitability. An agency that understands this is an agency that can actually help you grow.
The Final Checklist: What to Look For Before You Sign
Okay, you've done your homework. You've dissected their case studies, grilled them on a call, and you have a good feeling about them. Before you sign that contract and hand over your credit card details, run through this final mental checklist. This is where you bring it all together and make your final decision.
One last thing on due diligence: reviews and references. Reviews are helpful, but take them with a pinch of salt. It's easy to get friends and family to leave five-star reviews. Look for detailed reviews that talk about specific experiences and results. And what about asking to speak to one of their current clients? Here's another contrarian take: be careful with this. Tbh if a potential client asks us for references after they've already reviewed our detailed case studies and had a free, in-depth account review with us, it's an instant red flag. It signals a deep-seated lack of trust that probably won't go away. A good partnership is built on trust from the start. If you've done all the other steps right, you shouldn't need that final phone call.
The decision to hire an agency is a big one. But it doesn't have to be a blind leap of faith. By using this framework, you can move from being a passive buyer to an active, informed interviewer. You can cut through the noise and find a genuine partner who has the expertise to help you achieve your goals.
This is the main advice I have for you, all boiled down:
Your Agency Vetting Framework
| Vetting Step | What to Look For (Green Flags) | What to Avoid (Red Flags) |
|---|---|---|
| 1. Dissect Case Studies | Relevant niche, business-focused metrics (ROAS, CPL, Revenue), platform-specific results. Honesty about challenges. | Vague results, vanity metrics (clicks, impressions), irrelevant industries, no platform details. Only perfect stories. |
| 2. Interrogate on the Call | They ask you lots of questions, talk process and testing, give realistic projections, and provide real value/ideas on the call. | They promise guaranteed results, use a generic sales pitch, can't answer tough questions, dodge talking about numbers. |
| 3. Analyse Their Strategy | They start by understanding your customer's pain, propose a bespoke strategy, and justify their choice of platforms. | They push a "proprietary funnel", use a one-size-fits-all approach, and don't seem interested in your specific customer. |
| 4. Understand Your Metrics | They anchor their strategy to your business numbers (LTV, margins) and set targets based on profitability. | They talk about generic industry benchmarks without asking about your specific unit economics. |
So, Why Bother With an Agency at All?
After all this, you might be thinking, "This sounds like a lot of work, maybe I should just try and do it myself." You could. But paid advertising is a full-time job and a deep specialism that changes constantly. Doing it properly involves research, strategy, copywriting, design, technical setup, daily monitoring, analysis, and constant optimisation.
A good agency isn't just a pair of hands to run your ads. They bring years of experience from spending millions of pounds across hundreds of accounts. They've seen what works and what doesn't. They can help you avoid the costly mistakes that most businesses make when they start out, and they can help you scale much faster than you could on your own. You're not just paying for their time; you're paying for their accumulated knowledge.
If you're serious about growing your business with paid advertising and want an expert partner to guide you, we offer a completely free, no-obligation strategy session. We'll dive into your business, look at your current advertising (if any), and give you a straightforward, honest assessment of what we think is possible. It’s a chance for you to see if we're the right fit, and a chance for us to show you what real expertise looks like.