TLDR;
- Stop asking "Facebook or LinkedIn?" and start asking "Who is my customer?". The platform choice is a consequence of your audience, not the starting point.
- Targeting a "broad, undefined audience" with "no geo focus" is the fastest way to burn your entire ad budget. You are literally paying platforms to find you non-customers.
- LinkedIn is a surgical tool for when you know the exact job title, industry, and company size of your buyer. It's expensive but precise.
- Meta (Facebook/Instagram) is for scaling. It's powerful when your audience is defined by behaviours, interests, and problems, not just their professional role.
- This guide includes two interactive calculators: one to figure out your Customer Lifetime Value (LTV) and another to estimate your cost-per-result, helping you understand what you can actually afford to spend.
Asking whether to use Facebook or LinkedIn for a "broad, undefined audience" is like asking a builder whether to use a hammer or a screwdriver for "building something". The question itself is the problem, and it betrays a fundamental misunderstanding that will cost you thousands of pounds before you generate a single qualified lead. The raw truth is, there is no such thing as a good return on an undefined audience. You are simply paying for expensive noise.
The entire debate isn't about the platform; it's about your customer. Before you spend a single penny, you have to stop thinking about demographics and start thinking about nightmares. Your Ideal Customer Profile (ICP) isn't "a company in the finance sector." It's the Head of Compliance at that firm who is terrified of a new regulation that could lead to massive fines, and she's losing sleep over it. That specific, urgent, expensive pain is your targeting criteria. Everything else is a distraction.
In this guide, I'm going to show you how to stop wasting money and start making it. We'll dismantle the flawed premise of platform-first thinking and rebuild your strategy from the ground up, starting with the only thing that matters: the customer.
Your ICP is a Nightmare, Not a Demographic
Forget the sterile, demographic-based profile your last marketing hire made. "Companies in the finance sector with 50-200 employees" tells you nothing of value and leads to generic ads that speak to no one. To stop burning cash, you must define your customer by their pain. This is non-negotiable.
You need to become an expert in their specific, urgent, expensive, career-threatening nightmare. Your Head of Engineering client isn't just a job title; she's a leader terrified of her best developers quitting out of frustration with a broken workflow. For a legal tech SaaS, the nightmare isn't 'needing document management'; it's 'a partner missing a critical filing deadline and exposing the firm to a malpractice suit.' Your ICP isn't a person; it's a problem state.
Once you've isolated that nightmare, you can find them. Find the niche podcasts they listen to on their commute, like 'Acquired'; the industry newsletters they actually open, like 'Stratechery'; the SaaS tools they already pay for, like HubSpot or Salesforce. Are they members of the 'SaaS Growth Hacks' Facebook group? Do they follow people like Jason Lemkin? This intelligence isn't just data; it's the blueprint for your entire targeting strategy. Do this work first, or you have no business spending a single pound on ads. This approach is central to any successful paid social media advertising for B2B founders.
The reason this is so important is because of how the ad algorithms work. When you set a campaign objective to "Brand Awareness" or "Reach," you are giving the platform a very specific, and very stupid, command: "Find me the largest number of people for the lowest possible price." The algorithm, in its infinite wisdom, does exactly what you asked. It seeks out the users inside your targeting who are least likely to click, least likely to engage, and absolutely, positively least likely to ever pull out a credit card. Why? Because those users are not in demand. Their attention is cheap. You are actively paying the world's most powerful advertising machine to find you the worst possible audience for your product. You must always, always optimise for conversions—leads, sales, trials—so the algorithm is forced to find people who actually take action.
So, When Does LinkedIn Actually Make Sense?
LinkedIn is a surgeon's scalpel. It is not a sledgehammer. You use it when you need absolute precision and are willing to pay a premium for it. The cost per click can be 5-10x higher than on Meta, so if you don't have your numbers straight, you'll go broke very quickly. You should only consider LinkedIn under very specific circumstances.
The platform's power is its data. You can target people based on their exact job title, their seniority, the specific company they work for, the industry, and the company's size. This is its entire unique selling proposition. If your ICP is "VP of Sales at B2B SaaS companies in the UK with 50-200 employees," you can build that exact audience on LinkedIn. You can't do that with anywhere near the same accuracy on Meta.
I remember one B2B software client we worked with was selling a data enrichment tool. Their ICP was very specific: CMOs, CSOs, and Heads of Sales in the financial services and software industries. We ran a LinkedIn Ads campaign targeting these exact job titles and industries, driving them to a lead gen form. The cost per lead was around $22, which sounds high, but their customer LTV was well over $15,000. For them, paying $22 for a direct line to a key decision maker was a bargain. This is the kind of math that makes LinkedIn work. If your deal sizes are small, stay away. Many founders get this wrong and then complain that LinkedIn ads are useless, when in reality, their business model was just a poor fit for the platform.
If you fit the criteria, our complete guide to LinkedIn ads for B2B SaaS will walk you through the specifics of setting up a campaign that actually works. But the main takeaway is this: LinkedIn is for rifle shots, not shotgun blasts.
And When Should You Use Meta (Facebook/Instagram) Instead?
Meta is the opposite. It's a tool for scale, built on a massive dataset of user behaviours, interests, and connections. You use Meta when your ideal customer is defined more by what they *do*, *like*, or *talk about* than by their official job title. It's for finding the person who is obsessed with improving marketing ROI, regardless of whether their title is "Marketing Manager," "Founder," or "Growth Hacker."
For example, if you're targeting eCommerce store owners, simply targeting the job title "Owner" on LinkedIn is far too broad. But on Meta, you can target people who have an interest in "Shopify," "WooCommerce," are administrators of a Facebook Business Page, and also follow figures like Ezra Firestone. This creates a much more accurate and motivated audience profile.
The key to success on Meta is a structured approach to testing audiences. Too many people just throw a few interests into an ad set and hope for the best. This is a mistake. You need to think in terms of a funnel: Top of Funnel (ToFu), Middle of Funnel (MoFu), and Bottom of Funnel (BoFu).
| Funnel Stage | Audience Type | Description & Priority |
|---|---|---|
| ToFu (Cold) | Detailed Targeting | Start here. Target interests, behaviours, and demographics relevant to your ICP's pain points. (Priority 1) |
| Lookalike Audiences | Create lookalikes of your best customers, leads, or high-engagement website visitors. (Priority 2, once you have data) | |
| MoFu (Warm) | Website Visitors | Retarget people who visited your site but didn't convert. Exclude recent purchasers. (Priority 3) |
| Video Viewers | Retarget people who watched a significant portion (e.g., 50%) of your video ads. (Priority 4) | |
| BoFu (Hot) | Add to Cart / Initiated Checkout | Your highest-intent audience. Retarget people who started the buying process but didn't finish. (Priority 5) |
| Previous Customers | Upsell or cross-sell to your existing customer base. It's often your most profitable audience. (Priority 6) |
For one B2B software client, we used Meta ads to drive trial signups. By targeting interests related to their competitors and relevant industry publications, we generated 4,622 registrations at just $2.38 each. On LinkedIn, a similar lead would have cost upwards of $20. This is the power of Meta when used correctly. The audiences are broader, but if the interest and behavioural signals are strong, the algorithm can be incredibly effective at finding buyers at a much lower cost. Getting this right is often the difference between success and finding your Meta ads not converting.
How Do You Know What a 'Good' Return Actually Is?
Your question was about "the best return." This is a meaningless phrase without context. A 2x return might be fantastic for a high-margin software product but disastrous for a low-margin eCommerce store. 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 your LTV is the single most important piece of financial modeling you can do before you run ads. It transforms your advertising from a cost centre into a predictable growth engine. Most founders don't do this, and it's why they are always terrified of ad spend.
Here's the simple formula:
LTV = (Average Revenue Per Account * Gross Margin %) / Monthly Churn Rate
Let's break it down. Say you run a SaaS business:
- Average Revenue Per Account (ARPA): £500/month
- Gross Margin %: 80% (after server costs, support, etc.)
- Monthly Churn Rate: 4% (the percentage of customers you lose each month)
LTV = (£500 * 0.80) / 0.04 = £400 / 0.04 = £10,000
In this example, each customer is worth £10,000 in gross margin to your business over their lifetime. A healthy LTV to Customer Acquisition Cost (CAC) ratio is typically 3:1. 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. Suddenly, that $22 lead from LinkedIn doesn't seem expensive, does it? It looks like a bargain. This is the math that unlocks aggressive, intelligent growth. Understanding these numbers is absolutly fundamental to measuring and maximizing your paid ads ROI.
Why Does a Great Audience on the 'Right' Platform Still Not Convert?
So you've defined your ICP's nightmare, you've chosen the right platform, and you know what you can afford to pay. You launch your ads... and get nothing. Clicks, maybe, but no leads. This is an incredibly common problem, and it's almost always because of your offer.
The "Request a Demo" button is perhaps the most arrogant Call to Action ever conceived. It presumes your prospect, a busy decision-maker, has nothing better to do than book a 30-minute slot to be sold to. It is high-friction, low-value, and instantly positions you as a commoditised vendor. You must do better.
Your offer’s only job is to deliver a moment of undeniable value—an "aha!" moment that makes the prospect sell themselves on your solution. It must solve a small, real problem for free to earn the right to solve the whole thing.
-> For a SaaS company, the gold standard is a free trial (no card details required) or a freemium plan. Let them use the actual product. Let them feel the transformation. The product becomes the salesperson. You generate Product Qualified Leads (PQLs) who are already convinced, not Marketing Qualified Leads (MQLs) for a sales team to chase.
-> For a service business, you must bottle your expertise. A marketing agency could offer a free, automated SEO audit that finds their top 3 keyword opportunities. A data analytics firm could provide a free 'Data Health Check' that flags critical issues. For us, it's a 20-minute strategy session where we audit failing ad campaigns completely free. We solve a real problem upfront, which builds trust and demonstrates our value far more than any sales pitch ever could.
Your ad copy needs to reflect this value-first approach. Don't sell the product; sell the transformation. Use the "Before-After-Bridge" framework. For a FinOps SaaS, the ad would say: "Before: Your AWS bill just arrived. It’s 30% higher than last month, and your engineers have no idea why. After: Imagine opening your cloud bill and smiling. You see where every pound is going and waste is automatically eliminated. Bridge: Our platform is the bridge that gets you there. Start a free trial and find your first £1,000 in savings today." This is infinitly more compelling than "Best-in-class FinOps platform. Request a demo."
Okay, But Can I Just Target 'Worldwide' to Start?
This brings us to the other flawed part of your enquiry: "without focusing on any specific geographic location". This is a terrible idea, especially when you're starting out. The promise of a global audience is tempting, but in practice, it's a trap.
When you run a worldwide campaign, the algorithm will naturally gravitate towards the cheapest clicks and impressions. These are almost always found in developing countries. You will get a flood of low-cost traffic, but the quality will be abysmal. You'll get bots, click farms, and users who have no ability or intention to ever buy your product, especially if it's priced for a Western market. It completely pollutes your pixel data, teaching the algorithm to find more of the wrong kind of people, and making it much harder to optimise later on. We have seen this issue time and time again with clients looking for beta testers without a geo focus.
The professional approach is to start with the country or small group of countries where you believe your best customers are. Usually, this is your home market. Focus your budget there, get clear data, find what messaging works, and achieve profitability. Only then should you begin to methodicaly expand to other, similar markets (e.g., from the UK to the US, Canada, and Australia).
The cost per result varies dramatically by region. A lead in the US might cost £15, while a lead in India might cost £1. If you group them together, your "average" CPL will look decent, but you'll be hiding the fact that 95% of your budget is being wasted on leads that will never convert. The difference is stark.
What Should I Do First?
We've covered a lot of ground and dismantled the original question. The path forward isn't about picking a platform out of thin air; it's a strategic process. If you follow these steps, you will be miles ahead of your competition who are still boosting posts and targeting "business owners".
This is the main advice I have for you:
| Step | Action To Take | Why It Matters |
|---|---|---|
| 1. Define Your ICP's Nightmare | Forget demographics. Write down the specific, urgent, and expensive problem that your ideal customer is losing sleep over. What is their "before" state? | This is the foundation of all your targeting and ad copy. Ads that speak to a deep pain point get clicked; generic ads get ignored. |
| 2. Calculate Your LTV | Use the calculator in this guide to figure out what a customer is actually worth to you. Determine your maximum allowable Customer Acquisition Cost (CAC). | This turns advertising from a guessing game into a mathematical equation. It tells you what you can afford to pay and removes emotion from decision-making. |
| 3. Craft a No-Brainer Offer | Delete "Request a Demo". Replace it with a high-value, low-friction offer like a free trial, a freemium plan, or a free tool/audit that solves a small problem instantly. | A great offer reduces friction and proves your value upfront. It's the single biggest lever you have to improve conversion rates. |
| 4. Choose Your Platform | If your ICP is defined by Job Title/Industry and your LTV is high, start with LinkedIn. If your ICP is defined by behaviours/interests, start with Meta. | This ensures you are fishing in the right pond. You're aligning the platform's strengths with your specific customer profile. This is the core of our channel selection framework. |
| 5. Select Your Core Geography | Start with one country or a small, homogenous group of countries (e.g., UK & Ireland). Do not target "Worldwide". | This gives you clean, relevant data and prevents your budget from being wasted on low-quality traffic, allowing for proper optimisation. |
| 6. Launch & Optimise | Launch conversion-focused campaigns. Test your audiences (using the funnel structure for Meta) and creatives relentlessly. Cut what doesn't work and scale what does. | Paid advertising is not "set it and forget it". It requires constant vigilance and optimisation to remain profitable. |
This process is straightforward, but it isn't easy. It requires discipline and a willingness to do the strategic work before you even open an ads manager. But it is the only reliable way to get a real return on your investment.
Navigating this complexity is where professional help can make a dramatic difference. An experienced consultant has run this playbook hundreds of times across different industries. We can help you define your ICP, calculate your LTV, craft a compelling offer, and manage the entire campaign process to drive down costs and scale up results. If you've tried to run ads yourself and failed, it's likely one of these fundamental steps was missed. If you'd like an expert pair of eyes on your strategy, consider booking a free, no-obligation consultation where we can walk through your specific situation.
