TLDR;
- There is no single "best" platform; it depends entirely on whether your audience is searching for a solution (Google) or needs to be interrupted (LinkedIn/Meta).
- LinkedIn Ads are expensive (expect £8-£15+ per click in London) but offer the best targeting for specific job titles in Canary Wharf or the City.
- Google Ads capture high intent but are incredibly competitive in the UK SaaS market; you'll pay a premium for keywords like "accounting software".
- I've included a Budget Allocation Calculator below to help you estimate where to put your pounds based on your monthly spend.
- The most important advice: Don't just ask for a "Demo". Offer value first, or your Cost Per Lead will be sky-high.
If I had a pound for every time a founder asked me "What's the best ad platform for my SaaS?", I probably wouldn't need to run an agency anymore. It’s the most common question we get, and honestly, the answer usually disappoints them.
Because the answer is: It depends.
I know, I know. Typical consultant answer. But hear me out. If you are selling a generic project management tool to small agencies in Shoreditch, your strategy is going to look wildly different than if you're selling enterprise compliance software to banking execs in the City. One is hanging out on Instagram and Reddit; the other is strictly on LinkedIn or reading the FT.
Living and working in London, we see a specific micro-climate here. The competition is fierce. You aren't just bidding against other UK startups; you're bidding against US giants with massive dollar-pegged budgets trying to break into the EMEA market. This drives up CPCs (Cost Per Click) across the board.
So, let's break down the big three—Google, LinkedIn, and Meta—specifically for the London B2B SaaS market, and figure out where you should actually be putting your money.
The "Big Three" Comparison
Before we dive into the nitty-gritty, it helps to visualise the trade-offs. You are usually trading "intent" (how ready they are to buy) against "targeting" (exactly who they are) and "cost".
1. Google Ads: The "I Need It Now" Crowd
Google Ads is usually where I tell most B2B SaaS companies to start, especially if you are in the early stages. Why? Because you are capturing existing demand. You aren't trying to convince someone they have a problem; they are literally typing the problem into a search bar.
If someone searches for "best CRM for recruitment agencies London", they are practically waving a credit card in your face.
The Pros:
- Intent is king. Conversion rates are usually higher because the user is active.
- Speed. You can get clicks and data within hours of launching.
The Cons (especially in London):
- Cost. Competitor bidding is aggressive. For keywords like "fintech software" or "legal case management", I've seen CPCs in London hit £15-£30 just for a click.
- Scaling issues. There are only so many people searching for your specific solution each month. Once you tap that out, it's hard to scale further.
If you're wondering how this specific channel works for lead generation in our market, we have a deep dive on B2B SaaS Google Ads: UK Lead Gen that might be useful.
Strategy Tip: Don't just bid on "accounting software". That’s how you lose your shirt. Bid on "accounting software for small creative agencies". Long-tail keywords are your friend in a market as expensive as the UK. To understand specifically how to grow using this channel here, you might want to read our guide on Google Ads: The London B2B SaaS Growth Guide.
2. LinkedIn Ads: The Sniper Rifle
If Google is a net, LinkedIn is a sniper rifle. This is the only platform where you can say: "I want to show my ad to CTOs of Finance companies in London with 50-200 employees."
For B2B SaaS, this is often the "dream" targeting. But it comes with a nightmare price tag if you get it wrong. The CPMs (Cost per 1,000 impressions) on LinkedIn are easily 5-10x what they are on Facebook.
The Pros:
- Zero waste. You aren't paying to show ads to students or retirees (which happens on Google).
- Decision Makers. You get straight to the person signing the cheques.
The Cons:
- Friction. People are on LinkedIn to scroll their feed, brag about a promotion, or find a job. They are not there to buy software. You are interrupting them.
- Cost. Expect to pay £8-£12 per click minimum in the UK for senior audiences.
If you have a high Lifetime Value (LTV), LinkedIn is brilliant. If you are selling a £20/month tool, it's mathematically impossible to make a profit here. For a more detailed breakdown of how to make this work locally, check out our London SaaS: The Ultimate LinkedIn Ads Strategy.
3. Meta (Facebook & Instagram): The Wild Card
Most B2B founders laugh when I suggest Facebook or Instagram. "My customers are serious business people," they say. "They aren't on Instagram."
Yes, they are. Your "serious" CFO is scrolling Instagram on the tube home from Bank station just like everyone else. The difference is the context.
The Pros:
- Scale. Everyone is there.
- Cost. Much cheaper than LinkedIn. You can get traffic for £1-£2 per click.
- Retargeting. This is Meta's superpower. If someone visits your site from Google, follow them around on Instagram with case studies.
The Cons:
- Targeting is messy. You can't target by "Job Title" very well anymore. You have to rely on broad interests or lookalike audiences, which requires the algorithm to do the heavy lifting.
For founders looking to generate leads here, it requires a different creative approach. We've written a complete guide to Meta Ads for B2B SaaS lead generation that explains how to structure these campaigns differently from B2C.
The "London Factor": Why Location Matters
Running ads in London isn't like running ads in the rest of the UK. The density of tech companies here means ad inventory is premium.
We often observe that targeting London specifically can significantly increase the cost per lead compared to other UK regions. While a broad UK campaign might generate leads at a lower cost, narrowing down to the capital means you are bidding against every other prop-tech startup in Shoreditch for the same audience.
However, the value of London leads is often higher. They tend to have bigger budgets and adopt tech faster. If you are trying to decide between platforms specifically for this market, our data-driven comparison of Google, Meta, & LinkedIn Ads for UK businesses breaks down the numbers further.
Calculating Your Budget & Platform Mix
So, which one do you pick? Usually, you don't pick just one. You build a stack.
Seed Stage / Limited Budget (£2k - £5k/month): Go 80% Google Ads (capture intent) and 20% Meta (retargeting). Ignore LinkedIn for now; it's too expensive to learn on.
Series A / Growth (£10k+/month): 40% Google (max out intent), 40% LinkedIn (account-based marketing to target big logos), 20% Meta (retargeting and broad awareness).
I've built a calculator below to help you estimate the potential return based on typical London ad costs. Have a play with the sliders to see what your budget might get you.
The "Request a Demo" Trap
Regardless of which platform you choose, there is one mistake I see 90% of London SaaS founders make. They spend thousands of pounds driving traffic to a page that just says "Request a Demo".
This is the most arrogant Call to Action in marketing.
You are asking a busy decision-maker to give up 30 minutes of their day to be sold to. Unless they are already desperate for your solution (bottom of the funnel), they won't do it. This drives your Cost Per Lead through the roof.
What to do instead:
You need to offer value upfront. Create a tool, a template, or a piece of insight that solves a small part of their problem immediately.
- Selling HR software? Offer a "UK Employment Law Compliance Checklist".
- Selling FinTech? Offer a "R&D Tax Credit Calculator".
- Selling Cybersecurity? Offer a free "Domain Vulnerability Scan".
This is how you lower your CPL from £100+ to £30. You earn the right to talk to them.
Prioritising Your Audiences
When you start running ads, you can't target everyone. You need to prioritise based on who is most likely to convert. Here is the hierarchy we generally follow for our clients:
Many founders start at the bottom of this stack (Cold Targeting) because they want "new" people. But the highest ROI always comes from people who already know you. If you aren't running retargeting ads on Meta or LinkedIn to people who visited your pricing page but didn't convert, you are literally leaving money on the table.
Summary: My Recommendations
There is no magic bullet, but there is a logical starting point. Here is my straightforward advice for a London-based B2B SaaS:
| Scenario | Primary Platform | Secondary Platform | Strategy |
|---|---|---|---|
| People are searching for it (e.g. "CRM", "Payroll") |
Google Ads | Meta (Retargeting) | Capture intent. Retarget non-converters on social. |
| New Concept / Niche (No one knows it exists) |
Google (Brand) | Target job titles directly. Create demand via content. | |
| Low Budget (<£2k) | Google Ads | None | Focus entirely on high-intent long-tail keywords. |
| Enterprise Sales (ACV > £10k) |
Meta | Account Based Marketing. Target specific companies. |
Deciding on the right mix can be tricky, especially when you're spending your own runway. If you're still scratching your head about whether to drop £5k on LinkedIn or Google, it might be worth getting a second pair of eyes on your strategy.
For UK founders needing specific guidance on navigating these platforms, we have a detailed UK Founder's Guide to Finding Experts for B2B SaaS ads.
Need a hand? We offer a free initial consultation where we can look at your current setup (or lack thereof) and give you an honest assessment of where you should invest. No sales fluff, just a look at the numbers. Consider booking a chat with us.
