B2B SaaS: The London Guide To Google Ads Experts

I see this question a lot. You're a B2B SaaS founder, likely based in or around London, and you're drowning in a sea of agencies all promising to generate "qualified leads" with Google Ads. They've got slick offices in Shoreditch or Canary Wharf, they talk a big game, but when you dig a little, you realise they were running ads for a dog food brand last week. The truth is, finding a genuine specialist in London is tough, not because they don't exist, but because they're drowned out by the noise of generalists.

The problem is you're asking the wrong question. It's not about finding a "Google Ads agency in London". It's about finding a growth partner who understands the unique, painful journey of scaling a B2B SaaS business. That expertise isn't tied to a location. I've seen incredible SaaS-focused teams based in Manchester, Bristol, and even working fully remote who would run rings around the big, flashy London shops. So let's reframe this. Let's talk about how to find the *right* agency, regardless of their address, by looking for the right signals.

So, why is it so bloody difficult to find the right partner?

The London agency scene is a weird mix. You've got massive network agencies that are brilliant if you're a global brand like Nike, but they'll assign your £10k/month budget to a junior account manager who's still learning the ropes. Then you have hundreds of smaller "digital marketing" agencies that claim to do everything – SEO, social, email, ads. The problem is, B2B SaaS isn't just another 'vertical'. It's a completely different beast.

Think about it. Your sales cycle isn't 30 minutes; it can be 3, 6, or even 12 months. Your 'customer' isn't one person, it's a buying committee of five people with different titles and pains. The 'conversion' isn't a £50 purchase; it's a free trial sign-up that you need to nurture for weeks to turn into a paying customer. A generalist agency used to optimising for eCommerce sales will look at your account, see a high "cost per conversion" on a trial signup, and immediately panic, trying to get you cheaper but ultimately worthless leads. They don't understand that a single £300 lead that turns into a £20,000 annual contract is infinitely better than a hundred £5 leads who never even log in to the product.

You need a partner who gets that. Someone who doesn't just look at your Google Ads account, but asks to see your entire funnel, from the ad click to the landing page, the trial onboarding sequence, and the sales handover process. Most agencies in London don't have this depth of expertise becuase they are spread too thin across too many industries.

What should I be looking for instead of a postcode?

It boils down to proof, not promises. The single most important asset an agency has is its case studies. But you need to learn how to read them properly.

Don't just look for logos of other SaaS companies. Dig deeper. Ask these questions:

-> What was the actual business model? Was it a product-led growth (PLG) SaaS with a free trial, like you? Or was it a sales-led enterprise platform with a six-month sales cycle? The ad strategies are worlds apart. I remember a SaaS client we worked with in the recruitment space. They were burning money trying to get demo requests, but their product was perfect for a PLG motion. We helped them shift the ad strategy to focus on a free trial, and their cost per user acquisition dropped from over £100 to just £7. A generalist agency would never have had the insight to challenge the core offer.

-> Who was the target audience? Were they targeting CTOs and developers, or were they going after marketing managers at SMEs? A campaign targeting a technical audience requires completely different messaging and keyword strategies. If they can't show you experience with your specific Ideal Customer Profile (ICP), that's a massive red flag.

-> What were the real metrics? Don't be impressed by "10 million views" or a "50% increase in clicks." These are vanity metrics. You want to see the numbers that matter to a SaaS business. What was the cost per trial? What was the trial-to-paid conversion rate? How did the campaign impact their LTV:CAC ratio? If they can't talk about these things fluently, they haven't really done it before.

This vetting process is a funnel in itself. You start wide with your search, but you need to be ruthless in qualifying them based on this very specific evidence.

How do I know if they *really* get Google Ads for SaaS?

Running Google Ads for a SaaS product is an art form. It's so much more than just bidding on your competitor's brand name (which is often a poor strategy anyway). A true specialist will talk about a few key things.

First, intent-based keyword strategy. They should be able to break down your potential audience by where they are in their buying journey. Are they problem-aware (searching for "how to reduce my AWS bill"), solution-aware (searching for "cloud cost management software"), or brand-aware (searching for your competitor's name)? Each of these requires a different ad, a different landing page, and has a different expected cost per lead. If an agency just gives you a massive list of 200 keywords without this kind of strategic thinking, they're just guessing.

Second, they must be obsessed with your landing pages. I can't stress this enough. The best Google Ads campaign in the world will fail if it sends traffic to a poor landing page. An expert agency will give you direct, sometimes brutally honest feedback on your pages. They'll talk about headline-to-ad-copy match, social proof, the clarity of your call to action, and page load speed. In fact, many founders discover that their ad campaigns are failing because of fundamental landing page issues, not the ads themselves. The agency should be a partner in fixing this, not just a media buyer who blames the website when things don't work.

Finally, tracking and attribution. Standard "last click" attribution in Google Ads is almost useless for a SaaS business with a long sales cycle. A user might click an ad today, sign up for your newsletter, read three blog posts over the next month, and then finally sign up for a trial after a direct visit. A good agency will talk about setting up more sophisticated attribution models, or better yet, integrating your ad platforms with your CRM (like HubSpot or Salesforce) so you can track the entire journey and know which ads are *actually* generating revenue, not just initial signups.

What's the real cost? The maths you must do before hiring anyone.

Before you even think about agency fees or ad spend, you have to answer one question: "What is a new customer worth to my business?" If you don't know this, you're flying blind, and you can't possibly judge if an agency's performance is good or bad. This is where calculating your Customer Lifetime Value (LTV) comes in.

The calculation is simpler than it sounds:

LTV = (Average Revenue Per Account Per Month * Gross Margin %) / Monthly Customer Churn Rate

Let's break it down with a realistic UK example. Say you're a SaaS business selling to other SMEs:

• Your average customer pays you £400/month (ARPA).
• Your gross margin is 80% (after server costs, support, etc.).
• You lose 3% of your customers each month (your churn rate).

The LTV would be (£400 * 0.80) / 0.03 = £320 / 0.03 = £10,667.

This number changes everything. A healthy SaaS business aims for an LTV to Customer Acquisition Cost (CAC) ratio of at least 3:1. This means, for a customer worth £10,667, you can afford to spend up to £3,555 to acquire them. Suddenly, a £250 cost per demo from Google Ads doesn't look so scary, does it? If you know that 1 in 10 demos turns into a customer, you're paying £2,500 to acquire £10,667 in lifetime value. That's a great deal you should be trying to scale all day long.

Use the calculator below to get a feel for your own numbers. This is the most important piece of data you can bring to a conversation with a potential agency. It shifts the conversation from "can you get me cheap leads?" to "can you get me profitable customers at scale?".

Should they talk about more than just Google Ads?

Absolutely. If an agency only wants to talk about Google Ads, they're not a growth partner; they're a channel manager. The best results often come from an integrated approach. While Google Ads is fantastic for capturing existing demand (people already searching for a solution), other platforms are needed to *create* demand.

For B2B SaaS, that usually means LinkedIn Ads. The targeting is unparalleled. You can get your message in front of a Head of Engineering at Series B tech companies in London with 50-200 employees. The leads are more expensive, there's no question about it, but their quality can be incredible. A good agency will be able to discuss when and how to layer LinkedIn into your strategy. For a more detailed breakdown, we've written up a complete guide to using LinkedIn Ads for B2B SaaS which might be helpful.

They might also talk about Meta (Facebook/Instagram). While many dismiss it for B2B, we've seen fantastic results for SaaS clients, especially for products with a broad appeal or lower price point. One of our clients generated over 4,600 registrations for their B2B software at just $2.38 each using Meta Ads. The key is using its powerful lookalike audiences, built from your existing customer lists or high-intent website visitors. Deciding between platforms is a common headache, so understanding the pros and cons of Google Ads vs Meta Ads for B2B is a prerequiste for any sound strategy.

The chart below gives a rough idea of what you can expect in terms of lead costs across these platforms in the UK. Note that these are just averages; the real cost depends entirely on your specific audience, offer, and creative.

This is the main advice I have for you:

Choosing an agency is a big decision that can make or break your growth for the next year. Don't rush it, and don't be swayed by a fancy office or a slick sales pitch. Use this checklist as your guide during the selection process. Be the client who asks the tough, smart questions. The right agency will be excited to answer them; the wrong one will be exposed.

Ultimately, the challenge isn't a lack of agencies in London; it's a lack of specialised expertise. As a founder, your time is your most valuable asset. Trying to become a paid ads expert yourself while also building a product and a team is a recipe for burnout and mediocre results. The goal is to find a true partner who can take this off your plate and deliver predictable growth, freeing you up to do what you do best.

This process takes work, but it's far less costly than signing a 6-month contract with the wrong agency and watching your marketing budget go up in smoke. If you'd like a second opinion on your current strategy or want to see what a specialist approach looks like, we offer a completely free, no-obligation 20-minute strategy session where we can audit your existing campaigns and provide actionable advice. It's often the quickest way to see if there's a good fit and get some immediate value.

Hope that helps!