Finding a good YouTube ads agency in London feels like a proper task, doesn't it? The city's flooded with agencies all claiming they can get you amazing results. But the truth is, a lot of them are just good at selling themselves, not at actually running ads that make you money. It's easy to get burned by big promises that lead to a drained bank account and not much else. So instead of just googling and picking the one with the flashiest website, you need a bit of a process to see who's actually got the expertise and who's just full of it.
I've seen a lot of businesses jump into YouTube ads thinking it's a silver bullet, only to be disappointed. So before you even start talking to agencies, let's make sure it's the right move for your business in the first place. This is the first thing any decent agency should be asking you, by the way. If they just say "yeah, YouTube's great, let's go" without understanding your business, that's your first red flag.
Is YouTube Even the Right Place for Your Ads?
First off, think about your customers and what you're selling. YouTube is a visual platform. It works brilliantly if you have a product or service that you can demonstrate. Think about software that needs a walkthrough, a physical product that looks great in action, or a service where you can show off the results. I remember one campaign we worked on for an eLearning company selling courses where we generated over $115k in revenue in just over a month using Meta Ads because we could visually show snippets of the course content in the ads. That kind of thing is perfect for video advertising.
But it's not just about what you sell, it's about how your customers buy. Are they actively searching for a solution to their problem right now?
-> If they are, they're probably on Google Search typing in things like "emergency electrician near me" or "best accounting software for small business". In that case, Google Search ads might be a better starting point because you're catching them at the exact moment of need.
-> If they aren't actively searching, then you need to get in front of them and make them aware of the problem and your solution. This is where platforms like YouTube and Meta (Facebook/Instagram) come in. You can target people based on their interests, what channels they watch, or what they've searched for on YouTube before.
YouTube has a few different ad types, and a good agency will know which one to use for your specific goal:
- In-Stream Ads (Skippable): These are the classic ones that play before, during, or after a video. You only pay if someone watches 30 seconds (or the whole ad if it's shorter) or clicks on it. They're great for telling a story and driving traffic or leads. You need a really strong hook in the first 5 seconds before they can hit 'Skip Ad'.
- In-Feed Ads (Formerly Discovery Ads): These show up in YouTube search results and alongside related videos. Someone has to actively click to watch your ad, so they're usually more engaged. This is good for longer-form content, like a detailed product demo.
- Bumper Ads: These are short, 6-second, unskippable ads. You can't say much, but they are brilliant for brand awareness and staying top-of-mind, especially for retargeting people who've already visited your website.
The point is, the platform and ad format should match your goal. If an agency doesn't have a clear reason for why they're recommending a specific YouTube strategy over, say, Google Search or LinkedIn ads, they probably haven't thought it through properly.
How to Spot an Agency That Actually Knows What They're Doing
Okay, so you've decided YouTube is a good fit. Now you've got to wade through all the London agencies. Instead of being wowed by their sales pitch, you need to look for concrete proof of their expertise. This really comes down to three things: their case studies, how they handle the initial consultation, and what their reviews say.
A Deep Look at Their Case Studies
This is probably the most important bit of your research. Don't just glance at the logos on their website. You need to actually read their case studies. And you're looking for a few specific things:
-> Relevance: Have they worked with businesses like yours? It doesn't have to be the exact same niche, but if you're a B2B software company, you want to see they have experience with other B2B clients. If you're an eCommerce store, look for eCom case studies. For example, I remember a campaign for a medical job matching SaaS where we significantly reduced the cost per acquisition, and another campaign for a luxury brand launch focusing on brand awareness. The approach is completely different for each. An agency that specialises in getting leads for local plumbers might not be the best choice for launching a national subscription box.
-> Real Results: A case study that says "we got 10 million views for our client" is pretty much useless. Who cares about views if they didn't lead to any sales? The only time that's a good metric is if the goal was pure brand awareness, as was the case with one luxury brand launch we worked on, which generated 10 million views. What you really want to see are business metrics. Things like:
- Return On Ad Spend (ROAS): For instance, we generated a 691% Return for a women's apparel brand.
- Cost Per Acquisition (CPA) or Cost Per Lead (CPL): Or, we achieved a $22 CPL for B2B decision makers on LinkedIn. In one instance, we reduced a client's Cost Per Acquisition from £100 down to £7 for a medical job matching SaaS.
- Revenue Generated: And we generated $71k in revenue for a client selling maps and navigation products.
These are tangible results that affect a business's bottom line. If their case studies are full of vanity metrics like impressions, clicks, or views, be very sceptical. It usually means they couldn't get the results that actually matter.
-> Transparency: A good case study gives you a bit of context. What was the problem? What was the goal? What did the agency actually do to get the results? It doesn't need to give away all their secrets, but it should demonstrate a strategic approach. If it's just a headline and a big number, it's not that helpful.
You gotta be realistic though. If they have a case study showing a 10x return in a super easy niche, don't automatically assume they can do that for you in a highly competitive market. A good agency will be honest about this.
The Initial Consultation Call
Most decent agencies will offer a free consultation or an initial chat. This is your chance to interview them. Don't let them just run through a sales presentation. You need to ask them probing questions and see how they respond. Tbh, the best agencies will be interviewing you as much as you're interviewing them. They'll want to know if you're a good fit for them too.
Here’s what you should be looking for:
-> They Ask Smart Questions: Do they ask about your business goals, your target customer, your profit margins, your customer lifetime value? Or do they just ask what your budget is? An expert needs this information to build a proper strategy. If they don't ask, they're probably just going to apply a one-size-fits-all template to your account, which rarely works.
-> They Give You Actual Ideas: In our free consultations, we'll often do a quick review of what a potential client is currently doing and give them a few actionable suggestions on the spot. It gives them a taste of our expertise. If an agency is cagey and says "we can't give you any ideas until you sign the contract," they're either not confident enough or they dont have any ideas.
-> They Don't Promise the World: This is a massive one. In paid advertising, you can never, ever guarantee results. There are too many variables. The market, your competitors, your website's conversion rate, the quality of your offer... it's impossible to predict exactly what the CPA or ROAS will be. If an agency says "we guarantee we'll get you a 5x ROAS in the first month," run a mile. A real expert will talk in terms of realistic targets, testing, and optimisation based on data.
A little tip from our side: if a potential client has seen our detailed case studies, had a free strategy call with us, and then asks to speak to our existing clients for a reference, it's honestly a bit of a red flag for us. It signals a deep lack of trust that probably won't go away. If all the evidence we've provided isn't enough to build that initial trust, we're probably not a good fit to work together.
What Should You Expect to Pay for a London Agency?
This is the question everyone wants to know. It breaks down into two parts: the agency's fee and your actual ad spend (the money that goes to Google/YouTube).
Agency Fees
Agencies in London typically use one of three models:
- Percentage of Ad Spend: This is common. They'll charge something like 10-20% of whatever you spend on ads each month. The downside is that they have an incentive for you to spend more, even if it's not efficient.
- Flat Monthly Retainer: This is what we prefer. It's a fixed fee each month, regardless of your ad spend. It's clean, simple, and means our focus is on getting you the best results for your budget, not on getting you to spend more. Fees in London can range from £1,000 a month for a freelancer or small agency to £5,000+ for a larger one.
- Performance-Based: This sounds great in theory (e.g., "you only pay us per lead generated"), but it can be tricky. It often means the agency is incentivised to go for quantity of leads over quality, and it can get complicated to track properly.
Your Ad Spend Budget
How much should you spend on the ads themselves? An agency can't pull a number out of thin air. It should be based on your goals. The basic maths is:
(Number of customers you want) x (Your target Cost Per Acquisition) = Your monthly ad spend
The tricky part is knowing what a realistic Cost Per Acquisition (CPA) is. This varies massively. For a B2C eCommerce product, your CPA might need to be under £20 to be profitable. For a B2B SaaS product with a high lifetime value, a CPA of £200 might be fantastic. For example, I remember campaigns for consumer services where a lead cost £5 for a home cleaning company, and others for competitive HVAC services where a lead was closer to £60. A good agency will use their experience and tools to give you a realistic forecast before you start. But even then, it's just an estimate. The first month of any campaign is about gathering data to find out what your actual CPA is.
I've put together a rough table below to give you an idea of what costs can look like for different objectives in developed countries like the UK. These are general figures, and YouTube might vary, but the principles are the same. A good agency's job is to use their expertise in targeting and creative to get you to teh lower end of these ranges.
| Objective | Typical Conversion Rate | Example Cost Per Click (CPC) | Estimated Cost Per Result (CPA) |
|---|---|---|---|
| Lead/Signup (e.g., newsletter, free guide) | 10% - 30% | £0.50 - £1.50 | £1.60 - £15.00 |
| eCommerce Sale | 2% - 5% | £0.50 - £1.50 | £10.00 - £75.00 |
| B2B Demo/Trial Signup | 5% - 15% | £2.00 - £5.00 | £13.00 - £100.00+ |
As you can see, the numbers are all over the place. The key is that the agency you choose should be able to have an intelligent conversation about this with you, using your own business's numbers.
My Main Recommendations for You
Finding the right agency is a process of de-risking your investment. You're trying to find the partner who gives you the highest probability of success. It's not about finding someone who is cheap; it's about finding someone who won't waste your money. A good agency will pay for itself many times over in saved time and increased profits. A bad one will just be a cost centre.
I've detailed my main recommendations for a vetting process for you in the table below. If you follow this, you'll be in a much better position to tell the experts from the cowboys.
| Vetting Stage | What to Do | What to Look For (Green Flags) | What to Avoid (Red Flags) |
|---|---|---|---|
| Step 1: The Research | Go through their website with a fine-tooth comb. Read at least 3-4 of their case studies in detail. Check out their Google Reviews or Clutch profile. | Case studies with real business metrics (ROAS, CPA, Revenue). Experience in a similar industry. Reviews that mention good communication and strategy. | Vague case studies focused on views/clicks. No relevant experience. A flashy website with no substance or proof. Bad reviews mentioning poor results or communication. |
| Step 2: The Consultation | Book a free consultation call. Prepare questions about their process, strategy for your business, and reporting. | They ask lots of questions about your business and goals. They offer genuine, specific ideas. They're honest about challenges and set realistic expectations. | They make huge guarantees about results. They don't ask any deep questions. They're evasive about their process or just give you a generic sales pitch. |
| Step 3: The Proposal | Ask for a proposal outlining the scope of work, strategy, timeline, and all costs involved. | A clear, customised strategy based on your conversation. Transparent pricing with no hidden fees. Clear deliverables and reporting schedule. | A generic, copy-pasted proposal. Unclear pricing or long, confusing contracts. A focus on tasks (e.g. "we will make 5 ads") rather than outcomes. |
| Step 4: The Decision | Review everything and trust your gut. Are you confident these people can help grow your business? Do you feel you can have a good working relationship with them? | You feel like you're hiring a strategic partner who is invested in your success. You understand their plan and feel confident in their expertise. | You feel pressured to sign. You have lingering doubts about they're expertise or honesty. It feels like a purely transactional relationship. |
So, Why Hire an Expert Agency Anyway?
You might be thinking, "this sounds like a lot of work, maybe I should just try and run the YouTube ads myself". You can, of course. But the reality is that YouTube Ads is a complex beast. Getting the targeting right, producing video creative that actually converts, understanding the bidding strategies, setting up conversion tracking correctly... it's a full-time job. It's a minefield of wasted ad spend for the inexperienced.
The value of a good agency isn't just in the time they save you. It's in the costly mistakes they help you avoid. It's the access to years of experience across hundreds of campaigns. They've already spent millions on ads and learned what works and what doesn't, so you don't have to learn those lessons with your own money. The fee you pay them should be an investment that delivers a return, not just a cost.
Choosing the right partner is one of the most important marketing decisions you'll make. Take your time, do your homework, and don't be swayed by empty promises. Look for the proof.
If you want to have a chat about your specific situation and get an honest assessment of whether YouTube ads could work for you, we offer a free, no-obligation consultation call. We can take a look at your business and give you some straight advice on what we think your next steps should be.
Hope that helps!
