The Only 3 Digital Marketing Metrics That Matter
Your digital marketing dashboard is a beautifully designed lie.
It’s a colourful collection of charts and graphs that go up and to the right, making you feel a warm sense of progress. It’s reassuring. It’s also, for the most part, meaningless.
Most digital marketing metrics exist to make marketing people feel busy and justify their budgets to those who sign the cheques. They are not there to help you, the business owner, make better decisions. They are distractions.
So, let's cut the fat. Let’s talk about the numbers that matter. The ones that connect directly to the health and survival of your business.
- Focus on three key metrics: Customer Acquisition Cost (CAC), Customer Lifetime Value (LTV), and conversion rates to gauge business health.
- Vanity metrics distract from real progress; prioritise sanity metrics that connect directly to revenue and profit.
- Maintain a simple, one-page dashboard to track essential metrics and make informed marketing decisions effectively.
The Great Divide: Vanity vs. Sanity Metrics

Everything starts here. You'll forever be chasing your tail if you don't understand this distinction.
What Are Vanity Metrics? (And Why Your Brain Loves Them)
Vanity metrics are the numbers that are easy to measure and look good on paper, but don't correlate with business success.
Think:
- Social media followers
- Page views
- Impressions
- ‘Likes’ on a post
Your brain loves these. They provide a quick hit of dopamine. “Wow, 10,000 people saw our post!” It feels like a win. But it isn't. It's just noise.
I once had a client who was ecstatic about a TikTok video with two million views. They were convinced they’d made it. The answer was zero when I asked how many leads or sales it generated. Not one. Two million views, zero pounds. That’s a vanity metric in its purest form.
Sanity Metrics: The Numbers That Pay the Bills
Sanity metrics are different. They are tied directly to your business objectives. Usually, that means revenue and profit.
They answer the fundamental questions:
- How much does it cost us to get a new customer?
- How much is a customer worth to us over time?
- What percentage of interested people buy something?
These numbers are often less glamorous. They don't always go up. Sometimes they are stubbornly, frustratingly flat. But they tell you the truth. And in business, the truth is the only thing that sets you free. Or, at the very least, keeps the lights on.
The shift is simple but profound. You move from asking, “How many people saw it?” to “What happened as a result?”
The Holy Trinity: The Only 3 Metrics You Need to Obsess Over
You can ignore almost everything else if you get these three right. They form a simple, robust system for understanding your business's engine.
1. Customer Acquisition Cost (CAC)

This is the big one. Your CAC is the total cost of your sales and marketing efforts to acquire a new customer.
It answers the question: “How much did we have to spend to get Dave from Sheffield to buy one of our widgets?”
Why it's king: If you don't know this number, you fly blind. You have no idea if your marketing is a profitable investment or a money pit. You can't make informed decisions about your ad budget, pricing, or strategy.
How to calculate it (the simple way): Forget complex formulas for a moment. Start here:
CAC=Number of New Customers in that Period, Total Marketing & Sales Spend in a Period
Your “Total Marketing & Sales Spend” should include:
- Ad spend (Google, Facebook, etc.)
- Salaries for your marketing/sales staff (or a portion of your salary if that's you)
- Costs of any tools or software you use
The most common mistake is only counting ad spend. That's not the real cost. Your time isn't free.
2. Customer Lifetime Value (LTV)

If CAC tells you the cost, LTV tells you the prize. It’s the total profit (not revenue) you can expect from an average customer over their relationship with your business.
Why it matters: LTV gives context to your CAC. A £100 CAC might seem insane for a £50 product. But if that same customer returns five more times over the next two years, that £100 CAC suddenly looks like a brilliant investment.
LTV shifts your focus from short-term transactions to long-term relationships.
A quick estimation for new businesses: Calculating a precise LTV can be tricky if you're new. Don't get bogged down. A simple starting point is:
LTV=(Average Sale Value)×(Number of Repeat Transactions)×(Average Profit Margin)
If you don't have historical data, make educated guesses. You can refine it later. An educated guess is infinitely better than no number at all.
The Golden Ratio: LTV:CAC
This is where it all comes together. The relationship between what you spend to get a customer and what that customer is worth.
You want your LTV to be at least 3 times your CAC for a healthy, sustainable business.
- LTV:CAC of 1:1 means losing money with every new customer (once you factor in other business costs).
- LTV:CAC of < 3:1 means you have a thin margin for error. Things are tight.
- LTV:CAC of 3:1 or higher means you have a solid, scalable business model. For every £1 you put in, you get £3 back. Now you have a machine you can fuel.
This ratio is your master control. When the ratio is healthy, you can confidently increase your marketing spend. You know you need to decrease your CAC or find ways to improve your LTV when it's poor. Full stop.
3. Conversion Rate (The Real Ones)

“What's your conversion rate?” is a silly question. It's too vague. You need to be more specific, because different conversion rates tell you other things.
There are two things you need to separate:
- Visitor-to-Lead Conversion Rate: Of all the people who visit your website, what percentage take a small step to show interest? This could be signing up for a newsletter, downloading a guide, or filling out a contact form. This metric tells you if your marketing message and initial offer are compelling.
- Lead-to-Customer Conversion Rate: Of all the people who identified themselves as a lead, what percentage become a paying customer? This metric tells you if your sales process, pricing, and final offer are effective.
If your Visitor-to-Lead rate is high but your Lead-to-Customer rate is low, you have a sales problem, not a marketing problem. People are interested, but you're failing to close them.
If your Visitor-to-Lead rate is abysmal, then your marketing is failing. You’re attracting the wrong people, or your message is weak.
Separating them gives you clarity. Lumping them together just creates confusion.
Channel-Specific Metrics That Don't Suck (A Quick Guide)
Okay, the trinity is your strategic overview. But sometimes you need to look at specific channels to see what's working and what isn't. Here's a quick, no-nonsense guide.
For Your Website & SEO
Forget Bounce Rate. It’s an outdated and often misleading metric. A person can “bounce” after finding what they needed (like your phone number).
Instead, focus on these:
- Organic Traffic to Lead/Sale Conversion Rate: Don't just count visitors from Google. Count how many of them do something that matters. This is the accurate measure of your SEO success.
- Number of Commercially-Intent Keywords Driving Traffic: Are you ranking for “how to fix a leaky tap yourself” or “emergency plumber near me”? One is for information-seekers, the other is for buyers. Track the keywords that signal someone is ready to spend money.
For Your Paid Ads (Google, Facebook, etc.)
Click-through rate (CTR) is a classic vanity metric. A high CTR with zero sales means you're good at writing appealing ads that attract the wrong people.
Focus on the money:
- Cost Per Acquisition (CPA) / Cost Per Lead (CPL): This is a direct input into your overall CAC. You should know the maximum CPL or CPA you can afford for any campaign. If a campaign exceeds it, you kill it. Simple.
- Return On Ad Spend (ROAS): The big one. For every £1 you put into ads, how many pounds in revenue do you get back? A 4:1 ROAS (£4 out for every £1 in) is a standard benchmark for success, but it depends entirely on your profit margins.
If your ads aren't hitting your target CPA and ROAS, they aren't working. It doesn't matter how many clicks or “engagements” they get. If you struggle to make these numbers work, getting an expert eye on your campaigns might be time. That’s precisely what our digital marketing services are designed for—to cut through the noise and build profitable campaigns.
For Your Email Marketing
Open Rate is now officially a vanity metric. Thanks to Apple's Mail Privacy Protection, a huge chunk of “opens” are automatically triggered and don't represent a real person reading your email.
Look at what people do:
- Click-Through Rate (CTR): What percentage of people clicked a link in your email? This is the new baseline for engagement. It shows they were interested enough to take action.
- Conversion Rate from Email: How many people who clicked a link went on to buy or sign up? This is the ultimate test. Did your email generate business?
For Social Media (The Land of “So What?”)
This is the vanity metric capital of the world. Follower counts, likes, shares, and “reach” are mostly fantasy. Your follower count is not a business asset unless you are a full-blown influencer.
Bring it back to sanity:
- Website Clicks: Is your social media activity driving people to your website, where they can buy something?
- Conversions from Social: Use tracking links (UTM codes) to see how many clicks from social media turn into leads or sales. The numbers will likely be humbling, but they'll be true.
Building a Dashboard That Doesn't Give You a Headache
The goal is clarity, not complexity.
The One-Page Rule
Your core business metrics should fit on a single page or screen. If it doesn't fit, it's not a Key Performance Indicator, it's just a “Performance Indicator”. Ditch it.
Use a simple Google Spreadsheet or the free version of Google Looker Studio. You do not need to spend hundreds a month on a fancy analytics tool. More data is not the answer. Better insights from less data is.
The “What? So What? Now What?” Framework
Data is useless without interpretation and action. For every key metric on your dashboard, apply this simple framework.
- What? (State the data point): “Our Customer Acquisition Cost (CAC) increased by 20% last month.”
- So What? (Explain the implication): “This means our marketing is becoming less efficient and eating into our profit margins with every sale.”
- Now What? (Define the next action): “We need to analyse the performance of each ad campaign from last month, pause the worst-performing one, and reallocate that budget to the best one.”
This turns passive data-gazing into an active decision-making process.
How Often Should You Even Look at This Stuff?
Looking at your metrics daily is a recipe for anxiety and bad, twitchy decisions. You'll start changing things before you have enough data to know if they work.
A better cadence:
- Weekly: Check your channel-specific metrics (CPA, CTR from email, etc.). Look for major trends or red flags.
- Monthly: Review your Holy Trinity (CAC, LTV, Conversion Rates). Make strategic decisions. Is the business model working? Do we need to adjust pricing? Do we need to increase our marketing budget?
A Final, Brutal Truth About Attribution
Here's where so many small businesses waste countless hours. Attribution is the science of figuring out which marketing touchpoint gets the “credit” for a sale.
The Myth of Perfect Attribution
Most platforms use “last-click” attribution. If someone clicks a Google Ad and buys, Google gets 100% of the credit. But what if they first saw you on Instagram, read three of your blog posts, got an email, then searched for you on Google and clicked the ad? Which one “worked”?
The answer is: they all did.
Multi-touch attribution models try to solve this, but they are incredibly complex and require vast data. For 99% of small businesses, they are a complete waste of time.
I once sat in a meeting where a company spent an hour debating whether a £150 sale should be credited to their Facebook campaign or their email newsletter. Meanwhile, their overall company revenue had been flat for six months. They were busy rearranging the deckchairs on the Titanic.
A Better Way: Directional Insight
Forget perfect attribution. Aim for directional insight. Look at your blended numbers.
Ask better questions:
- “We doubled our SEO budget three months ago. Has our overall volume of inbound leads increased?
- We ran a major promotion on our email list last week. Did overall sales see a noticeable spike?”
Look for correlation, not perfect causation. Is the business moving in the right direction when you do more of a particular activity? Good. That’s all you need to know. Don't let the pursuit of perfect data stop you from making good decisions.
Clarity, Not Complexity
The purpose of tracking metrics is not to have more charts. It's to gain clarity.
It’s about knowing your business so well that you can answer three questions with confidence:
- How much does it cost me to get a customer? (CAC)
- How much are they worth to me? (LTV)
- How effectively do I turn prospects into payers? (Conversion Rates)
Everything else is just a detail.
So, close the 27 analytics tabs you have open. Create a simple, one-page dashboard with a few digital marketing metrics we've discussed. Check it weekly. Think about it monthly. And spend the rest of your time talking to customers and improving your product.
That’s how you build a business that lasts.
Ready to stop guessing and start building a marketing engine based on the correct numbers? The team at Inkbot Design focuses on strategies that deliver measurable results. If you’re ready for a no-nonsense approach to growing your business, request a quote today. Or, feel free to browse more of our brutally honest advice on the blog.
Frequently Asked Questions (FAQs)
What are a small business's most important digital marketing metrics?
The “Holy Trinity”: Customer Acquisition Cost (CAC), Customer Lifetime Value (LTV), and your core Conversion Rates (Visitor-to-Lead and Lead-to-Customer). These three give you a complete picture of your marketing's profitability and effectiveness.
How do I calculate Customer Acquisition Cost (CAC) if I'm a one-person business?
You must include the value of your own time. Estimate how many hours you spend on marketing and sales each month and assign a reasonable hourly rate to that time. Add that “salary” cost to your direct spends (like ads and software) to get a valid CAC.
What is a good LTV:CAC ratio?
A benchmark for a healthy, scalable business is a ratio of 3:1 or higher. For every £1 you spend to acquire a customer, you generate £3 in profit over their lifetime. A 1:1 ratio means you are losing money on each new customer.
Should I ignore vanity metrics like followers and likes entirely?
You shouldn't obsess over them, but you don't have to ignore them completely. Think of them as a faint signal. A sudden spike in engagement on a particular topic might give you an idea for a new product or blog post. Just never, ever mistake them for business results.
My bounce rate is high. Is that always a bad thing?
Not necessarily. Bounce rate simply means a user viewed a single page and then left. If a user landed on your contact page, found your phone number, and called you, that's a “bounce” but also a perfect conversion. Focus on more meaningful metrics like time on page or conversion rates instead.
Why is Return on Ad Spend (ROAS) more critical than Click-Through Rate (CTR)?
CTR only tells you if your ad was enticing enough for someone to click. ROAS tells you if those clicks led to revenue. A high CTR with a low ROAS means you're effectively paying for useless clicks. ROAS measures the business impact, while CTR only measures the ad's surface-level appeal.
How can I track conversions if I don't sell products directly on my site?
You define a conversion as the most valuable action a user can take. For a consultant, it could be filling out a contact form. For a B2B service, it might be downloading a case study or booking a demo. These are “macro-conversions” that you track as the primary goal of your website.
Are email open rates completely useless with Apple's privacy changes?
They are unreliable and should no longer be considered a key performance indicator. Many “opens” are now automatically generated by Apple's servers, not human users. Instead, focus on the Click-Through Rate and the conversions generated from your emails.
What's the simplest way to start tracking these metrics?
Start with a simple spreadsheet. Create columns for your monthly marketing spend, including the number of new customers, CAC, average sale price, and leads generated. Manually update it once a month. Gathering and inputting the data will give you a powerful, intuitive feel for the numbers.
How long should I wait before deciding if a marketing campaign is a failure?
It depends on your sales cycle, but you must give it enough time and budget to gather meaningful data. Don't decide after one day and £10 in ad spend. Let a campaign run until it has generated a statistically significant number of clicks or impressions (e.g., at least 1,000 impressions or 100 clicks) before judging its CPA or conversion rate.