CAC

What is CAC (Customer Acquisition Cost)?

CAC, or customer acquisition cost, is a key metric in digital marketing because it shows the total cost of acquiring a new customer. It gives you a clear picture of how effectively your sales and marketing actually convert potential leads into paying customers. CAC covers both paid activities such as advertising and the resources you spend on organic efforts, branding and sales.

CAC lets you understand the financial relationship between what you invest and what you get back in the form of customers. The figure therefore works as a kind of health check on your business model. A high CAC may, for example, indicate that your marketing isn't hitting the mark, that your conversion rate is low or that your sales process is too complex. A low CAC, on the other hand, means you get more out of your marketing budget — especially if your customers also have a high lifetime value (LTV).

How does CAC work?

You calculate CAC with a simple formula, but the result depends on how accurately you include the relevant costs. The metric is calculated as:

Total costs can cover everything from Google Ads and social media to salaries for the sales team and software licences. If, for example, you spend DKK 500,000 on marketing in a month and gain 2,000 new customers, your CAC is DKK 250 per customer. However, this simple expression hides a complex picture, because spending on branding, content production and ads rarely takes effect at exactly the same time. That's why you should always calculate CAC over a period that matches your sales cycle.

Why is CAC important?

CAC is important because it gives you insight into how sustainable your business is. When you compare CAC with your customers' average lifetime value, you can assess whether you're spending too much on attracting new customers relative to what they actually contribute in the long term. A rule of thumb is that LTV should be at least three times higher than CAC for a profitable model.

Just as importantly, CAC often reveals how your marketing channels perform relative to each other. If your CAC is lowest through SEO and email marketing but high on paid advertising, it may be a sign that you should optimise your campaigns or widen your focus to include organic growth. That way, CAC becomes a management tool that lets you shift budgets and prioritise channels with proven results — areas where SEO, Google Ads and social media advertising in particular can make a significant difference.

What types and variants are there?

You can calculate CAC across channels, but results vary depending on the medium and your product. In practice, many people split it up like this:

• Google Ads: Often medium to high CAC, but customers come with strong purchase intent
• Facebook and Instagram: Typically lower CAC when you reach your audience with creative content and precise targeting
• SEO: Relatively low CAC over time, because visitors arrive organically without cost per click, although building it up requires investment in content and technical optimisation
• Email marketing: Very low CAC, as long as you've built a quality segment of subscribed recipients

You can also segment your CAC by factors such as customer type, industry, lead quality or sales cycle. This gives you a more nuanced understanding of where your money works best. If, for example, you discover that CAC for B2B customers is twice as high as for B2C, you may want to consider whether your strategy for lead nurturing and sales readiness should be adjusted.

How do you work with CAC in practice?

Working effectively with CAC takes both data insight and cross-functional collaboration. First, you need to define which costs should realistically be included in the calculation. That covers direct ad spend, video production and graphic design, as well as salaries, software and any agency fees. You then need to monitor developments continuously to spot fluctuations and trends, so you can react quickly.

You can reduce CAC in several ways. Some of the most effective involve improving the conversion rate on your landing pages and ad flows. For example, when you optimise search ads through a better keyword structure and the use of negative keywords, you minimise waste and improve relevance. The same applies when you work strategically with SEO and content marketing to attract users without paid clicks. In other words: the more qualified visitors you get through organic channels, the lower your average CAC becomes over time.

Another effective approach is to use existing customers as ambassadors. Referral programmes or email automation flows to past customers can generate new purchases at minimal cost. Similarly, retargeting ads can help you convert users who already know your brand, which almost always gives a lower CAC than reaching entirely new audiences.

What should you be aware of?

Although CAC is an important KPI, you shouldn't view it in isolation. A low CAC doesn't necessarily mean your business is healthy if your customers also have a low LTV or high churn. You should therefore always look at CAC in the context of the entire customer journey. This is where it pays to work strategically with branding, content and customer loyalty, because investing in relationships over the long term can lower your cost per customer.

Also keep an eye on hidden influences. When, for example, you invest in a stronger visual identity or digital design, it can have an indirect but significant effect on CAC, because a better experience increases the likelihood of purchase. Similarly, improved data setup and ongoing optimisation in Google Ads can give you more precise insight into what each customer actually costs, so you can make better decisions about future investments.