London Paid Ads: The Founder's Playbook

Starting out with paid ads in London is a daunting task. It feels like every agency and 'guru' is shouting about a different platform or a new magic bullet strategy. The truth is, most of it is noise. The reason you're overwhelmed is because you're starting in the wrong place. You're thinking about tactics—the ads, the platforms, the budgets—before you've sorted out the one thing that actually matters: your strategy. Without a solid foundation, you're just setting money on fire, and in London's hyper-competitive market, that fire burns very, very fast.

So let's cut through the rubbish. I'm going to give you the exact framework we use for our clients, a straightforward, no-nonsense playbook for getting started with paid customer acquisition in London. This isn't about chasing trends; it's about building a machine that reliably turns ad spend into profitable customers.

So, who am I actually trying to reach in this city of 9 million people?

First things first, tear up that ideal customer profile (ICP) your last marketing intern made. "FinTech companies in Canary Wharf with 50-200 employees" is a useless starting point. It tells you nothing of value and leads to generic, boring ads that get ignored. To stop burning cash, you must define your customer by their pain. By their nightmare.

You need to become an expert in their specific, urgent, and expensive problem. Your Head of Compliance client isn't just a job title; she's a leader terrified of a new FCA regulation causing a massive fine that could sink the company and her career. For a legal tech SaaS targeting firms around Chancery Lane, the nightmare isn't 'needing better document management'; it's 'a partner missing a critical filing deadline, exposing the firm to a malpractice suit and a damning headline in The Law Society Gazette.' Your ICP isn't a person; it's a problem state.

Once you've isolated that nightmare, you can find them. Where do they hang out online? They're probably not scrolling through broad Facebook feeds. Are they listening to niche podcasts like 'Fintech Insider' on their commute into Bank station? Are they reading industry newsletters they actually open, like 'Stratechery'? What software do they already pay for, like Salesforce or HubSpot? This is the intelligence that forms your entire targeting strategy. Do this work first, or you have no business spending a single penny on ads.

How do I know what I can afford to spend on ads?

The single biggest mistake I see founders make is focusing on the wrong metric. They obsess over Cost Per Lead (CPL) without knowing what a lead is actually worth. The real question isn't "How low can my CPL go?" but "How high a CPL can I afford to acquire a truly great customer?" The answer lies in its counterpart: Lifetime Value (LTV).

Calculating this isn't complex, but it's the most powerful thing you can do for your marketing. Here's the simple maths:

• Average Revenue Per Account (ARPA): What do you make per customer, per month? Let's say it's £500.
• Gross Margin %: What's your profit margin on that revenue? Let's say it's 80%.
• Monthly Churn Rate: What percentage of customers do you lose each month? Let's say it's 4%.

Now, the calculation is straightforward:
LTV = (ARPA * Gross Margin %) / Monthly Churn Rate
LTV = (£500 * 0.80) / 0.04
LTV = £400 / 0.04 = £10,000

In this example, each customer is worth £10,000 in gross margin to your business. This number changes everything. Suddenly you have clarity. A healthy 3:1 LTV to Customer Acquisition Cost (CAC) ratio is a good benchmark. This means you can afford to spend up to £3,333 to acquire a single customer. If your sales process converts 1 in 10 qualified leads into a customer, you can afford to pay up to £333 per qualified lead. It's a simple bit of maths, but it's fundamental to building a scalable performance marketing strategy that actually works.

That £250 lead from a CTO you targeted on LinkedIn doesn't seem so expensive now, does it? It looks like a bargain. This is the maths that unlocks aggressive, intelligent growth. Use the calculator below to figure out your own numbers.

Right, so which ad platform should I actually use?

This is where most founders get stuck. There's Google, Meta (Facebook & Instagram), LinkedIn, TikTok... the list goes on. The key isn't to be everywhere. It's to be on the right one, first. Your choice depends entirely on one question: Is your ideal customer actively searching for a solution to their problem right now?

If YES (they are problem-aware and searching): Your answer is Google Ads. This is for high-intent, immediate needs. Think of a finance director searching for "small business accountants in the City of London" or a homeowner in Islington looking for an "emergency plumber." They have a problem and they want it solved now. For these kinds of businesses, Google Search Ads are a non-negotiable starting point. I remember one campaign we worked on for a home cleaning company which got a cost of £5/lead by targeting people actively searching for their service. It's direct, effective, and captures demand that already exists.

If NO (they are not actively searching, but have the problem): Your answer is Meta or LinkedIn. Here, you need to create the demand. You're interrupting their day with a compelling message about a problem they might not even be focused on at that moment.

• LinkedIn Ads: This is your go-to for B2B, especialy in London. The targeting is unmatched. Want to reach Heads of Marketing at Series B tech companies based around Old Street? You can do that. Want to get in front of partners at law firms in Holborn? You can do that too. It's more expensive, but the quality of the lead can be phenomenal. One campaign we worked on for a B2B SaaS client generated leads from decision makers for around $22 a pop, which is great value when you know your LTV.
• Meta Ads (Facebook & Instagram): This is the king for most B2C businesses and some types of B2B (especially those targeting small business owners). Think e-commerce, apps, courses, local services. One campaign we worked on scaled an e-learning business to $115k in revenue in under two months using Meta ads. The algorithm is incredibly powerful at finding buyers if you feed it the right data (i.e., you optimise for conversions, not useless metrics like 'reach').

Don't try to master all of them at once. Pick one based on your customer's behaviour, and get it working profitably before you even think about the next. The flowchart below should help you decide.

What should my ads actually say to cut through the noise?

Your ad copy's only job is to get the right person to stop scrolling and click. In a city like London, where people are bombarded with thousands of messages a day, you can't afford to be vague or boring. You must speak directly to the 'nightmare' you identified earlier.

For a high-touch service business, use the Problem-Agitate-Solve formula. You don't sell "fractional CFO services" to a tech startup in Shoreditch; you sell a good night's sleep. Your ad would say, "Are your cash flow projections just a shot in the dark? Worried you're one bad month away from a payroll crisis while your competitors on Silicon Roundabout are confidently raising their next round? Get expert financial strategy for a fraction of a full-time hire. We build dashboards that turn uncertainty into predictable growth."

For a B2B SaaS product, you use the Before-After-Bridge formula. You don't sell a "FinOps platform"; you sell the feeling of relief. Your ad would say, "Your AWS bill just arrived. It’s 30% higher than last month, and your engineers have no idea why. Another fire to put out. Imagine opening your cloud bill and smiling. You see where every pound is going, and waste is automatically eliminated. Our platform is the bridge that gets you there. Start a free trial and find your first £1,000 in savings today."

Notice the pattern? You lead with the pain, you twist the knife a little by showing them what the future looks like if they don't solve it, and then you present your product as the obvious solution. It's direct, it's emotional, and it works.

Why the 'Request a Demo' button is killing your London campaigns

Now we get to the most common failure point in B2B advertising: the offer. The "Request a Demo" button is possibly the most arrogant Call to Action ever invented. It presumes your prospect, a busy London decision-maker, has nothing better to do than book a 30-minute slot in their diary to be sold to. It's high-friction, low-value, and instantly positions you as just another commodity vendor.

Your offer’s only job is to deliver an "aha!" moment of undeniable value that makes the prospect sell themselves on your solution. For us, as a B2B advertising consultancy, it's a 20-minute strategy session where we audit failing ad campaigns completely free. We solve a small, real problem for free to earn the right to solve the whole thing.

If you're a SaaS founder, your unfair advantage is the product itself. The gold standard is a free trial or a freemium plan (no card details needed). Let them use it. Let them feel the transformation. When the product proves its value, the sale is just a formality. You're not generating Marketing Qualified Leads (MQLs) for a sales team to chase; you're creating Product Qualified Leads (PQLs) who are already convinced.

If you're not a SaaS company, you're not exempt. You must bottle your expertise into a tool or asset that provides instant value. A marketing agency could offer a free, automated SEO audit. A data analytics platform could offer a free 'Data Health Check'. You have to give value before you ask for a meeting. Especially in London, where your prospects' time is their most precious resource.

What results can I realistically expect here?

This is the million-pound question. Costs in London are higher than in many other parts of the UK, but so is the potential value of a customer. It all comes back to your LTV. If you know a customer is worth £10k, paying £100 for a qualified lead is a no-brainer. The numbers below are based on our own client campaigns, primarily in the UK and other developed markets, so they're a realistic benchmark for what you might see.

For something like a lead, a signup, or a newsletter subscriber, you could be looking at a Cost Per Result anywhere from £1.60 to £15. I remember one campaign we worked on for an app that was getting signups for under £2 each, which was fantastic. Another for a B2B software company got 4,622 registrations at about $2.38 each. It really varies, but this is the ballpark.

For e-commerce sales or high-friction B2B leads (like filling out a long form), costs will naturally be higher because the commitment is greater. A typical Cost Per Purchase can range from £10 to £75, or even more for high-ticket items. But here, the metric that matters is Return On Ad Spend (ROAS). Are you getting more back than you're putting in? We've seen a 1000% ROAS for a subscription box client and a 691% return for a women's apparel brand. It's absolutly possible to be highly profitable, but you need patience and a rigorous testing process.

Okay, I'm ready. What does my first campaign look like?

Don't overcomplicate it. Your first goal is to get data and prove that you can acquire customers profitably on one platform. Let's assume you're using Meta Ads, as it's the most common starting point. Here's a simple, effective structure to begin with.

Create one campaign with the objective set to 'Sales' or 'Leads' (whatever your main goal is). Inside that campaign, create three different ad sets:

1. Ad Set 1: ToFu (Top of Funnel) - Prospecting. This is where you find new people. Your audience will be based on detailed targeting - the interests, behaviours, and demographics you figured out when you were defining your customer's nightmare. Group related interests together. For example, if you sell high-end coffee beans, you could target people interested in 'Speciality coffee', 'James Hoffmann', and brands like 'Square Mile Coffee Roasters'.
2. Ad Set 2: MoFu/BoFu (Middle/Bottom of Funnel) - Retargeting. This is for people who've already shown some interest but haven't converted. Create a custom audience of everyone who has visited your website in the last 30 days but excluded anyone who has already purchased or become a lead. Show them a slightly different ad, maybe with a testimonial or overcoming a common objection.
3. Ad Set 3: LAL (Lookalike Audience). Once you have at least 100 purchases or leads, you can create a Lookalike Audience. This is where you tell Meta: "Go and find me more people who look just like my existing best customers in the UK." This is often the most powerful and scalable audience you can build.

In each ad set, test 2-3 different ads (creatives). One might be an image, one a short video, another a carousel. Let them run for a few days. The data will quickly tell you which audiences and which ads are working. Turn off the losers, and put more budget behind the winners. It's a simple process of iterative testing. I've detailed my main recommendations for you to start with below:

This sounds like a lot of work...

It is. And that's why so many businesses in London fail at it. They treat paid advertising like a lottery ticket, throwing a few hundred quid at a campaign and hoping for the best. It's not a lottery ticket; it's a machine. And like any machine, it needs to be built correctly, with the right parts, and then constantly monitored and tuned.

Navigating this landscape, especially in a market as fierce and expensive as London, requires expertise. The difference between burning through your seed funding and building a scalable customer acquisition engine often comes down to experience—knowing which levers to pull, which metrics to ignore, and how to interpret the data to make smart decisions quickly.

If you've read this far and you feel that building and managing this machine yourself is taking you away from what you do best—running your business—then it might be time to consider getting expert help. We offer a completely free, no-obligation 20-minute strategy session where we can look at your business, your goals, and help you build a clear action plan. We'll give you honest, actionable advice you can implement right away. If it seems like a good fit for us to work together after that, great. If not, you'll still walk away with a ton of value and a clear path forward.