Unit Economics for Startups — What Are They & Why Are They Important?

While the concept might seem daunting at first glance, it's really about understanding some key metrics and how they work together. 

To calculate unit economics, you'll be dealing with factors like lifetime value (LTV), customer acquisition cost (CAC), churn rate, and others. The fundamental relationship underpinning unit economics is the ratio between LTV and CAC – simply put, it's about how much value a customer brings to your business versus how much you spend to acquire them. 

This isn’t the only aspect to consider, though; churn rate, retention rate, and average customer lifetime value all come under the wider umbrella of unit economics. The aim is to track and improve these metrics, ensuring your startup not only sustains growth but grows profitably.

Unit economics is the method of determining the profitability of a business on a granular level, typically measured on a per-customer or per-unit basis. It involves the quantification of direct revenues and costs to establish whether or not a profit can be made from each unit. This method allows businesses to forecast break-even points gross margins and can inform financial planning efforts.

In essence, unit economics looks at the value that each individual unit – a customer, a product, or a subscription – brings to the business and compares it against the cost it takes to acquire that unit. It's a tool that simplifies the complexity inherent in business operations, making it easier to measure and analyze profitability on a case-by-case basis.

Understanding and tracking unit economics is beneficial for several reasons. 

First of all, it gives you an early success metric for your business – especially for startups in their early growth stages. It helps in identifying growth patterns and projections supporting data-driven decision-making around budget allocations toward sales and marketing.

Secondly, it’s instrumental in managing cash flow and optimizing business models. Regular evaluations of these metrics can provide insights into financial performance and identify the most relevant opportunities for optimization and overcoming scaling challenges. This knowledge is essential in maintaining the sustainability and longevity of a business as it scales.

Contextually, there are several key metrics used in calculating unit economics. These include lifetime value (LTV), which explains how much revenue each customer will likely generate over their lifespan as a customer, and customer acquisition cost (CAC), which shows all direct and indirect costs accrued while acquiring new customers. The relationship between these metrics is important to keep in mind since an optimal LTV to CAC ratio for SaaS businesses is generally considered to be 3:1.

Another important metric is the CAC payback period, which indicates how quickly the cost of acquiring a new customer will be earned back. Shorter payback periods can allow for faster growth. Let’s look at each of these key metrics in detail.

Lifetime Value

Think of lifetime value as the monetary worth attributed to a customer over the entire relationship they have with your business. It measures how much revenue each customer will generate over their lifetime with your company. 

You calculate it by first determining the average monthly gross profit per customer and then multiplying that by their estimated lifespan based on the churn rate. As a rule of thumb, if your LTV is three times more than your customer acquisition cost, you're on the right track.

Customer Acquisition Cost

When you hear the term customer acquisition cost (CAC), think about the amount of money a business invests to gain a new customer. This cost includes all the direct and indirect expenses involved in introducing new customers to your product or service. 

For example, if you spend $10,000 on marketing in a month and onboard ten new customers, your average CAC is $1,000. The CAC is especially important for businesses when it comes to budgeting and managing cash flow. Always keep in mind that a business thrives when the lifetime value of a customer surpasses the CAC – this should be one of your primary tracked metrics.

Churn Rate

Churn rate isn’t as complex as it sounds – it's the percentage of customers who stop using or buying your product or service over a certain period. 

For businesses with subscription-based models, this is a critical number to monitor. A high churn rate signals that customers are leaving you at a faster rate, which can have significant impacts on your revenue. On the flip side, a lower churn rate indicates satisfied customers who continue to use your product or service, contributing to your LTV.

You should know by now that it’s crucial for you to understand how much you earn from a customer or unit and then compare it to the cost of acquiring that customer – this is the basis of unit economics. But do you know how to calculate each of these values by hand?

Let's look at a few methods used to calculate unit economics: the lifetime value to customer acquisition cost (LTV/CAC) ratio and the contribution margin per item.

A basic way to look at unit economics is to find out the lifetime value of a customer (LTV) and divide it by the cost it took to get that customer (CAC).

Let's say you have an online subscription service. The LTV is the total money a customer gives you over time, minus any costs you have to cover to keep them as a customer. For example, if a customer stays with you for three years, pays $100 each year, and costs you $50 each year for things like support, their LTV is $150 (that’s $300 in total payments minus $150 in total costs).

On the other hand, CAC is all the money you spend to get a new customer, like marketing, sales, and special offers. If you spend $75 to get that customer, your LTV/CAC ratio is 2 ($150 LTV divided by $75 CAC). This means you’re earning double what you spent to get each customer.

But remember, a good ratio doesn’t mean you’re all set. You should also think about how quickly you get your CAC back because tying up too much money for too long can slow down your growth.

Another way to look at unit economics is by focusing on the contribution margin per item. This helps you see how profitable each item sold is.

Imagine you sell a physical product, and create a “unit” for each sale. You find out the unit economics by taking the money you get from a sale, and then subtracting the costs like making the product, delivering it, and any after-sale service. For example, if a customer buys your product for $50, and it costs you $15 for production, shipping, and so on, your contribution margin per item is $35 ($50 sale - $15 costs).

This way, you can see the profit for each item or group of customers, and adjust your pricing or costs to do better. It also shows how making more sales affects your profits. If your contribution margin is positive, that's a good sign you're on the right track.

Grasping unit economics arms you with the power to discern how profitable your business can be down to the very granular level of each customer or product. Even more importantly, it shines a light on key performance metrics such as your LTV/CAC ratio and payback period, which give very critical insights into the efficiency and effectiveness of your customer acquisition strategies.

If you’re a startup founder working on growing your business, make it common practice to incorporate unit economics into your business model. Regularly evaluate direct revenues and costs, calculate accurate LTVs, measure churn rates, and keep an eye on CACs. 

Recognize the importance of defining what constitutes a “unit” in your specific business context and model, and never forget that iterating and optimizing are key components of any successful enterprise. By understanding and applying unit economics, you can navigate your way to a sustainable and scalable venture in today’s modern business world.