Understanding Customer Acquisition Cost (CAC) in Growth Marketing

Customer Acquisition Cost (CAC) is a crucial metric for businesses to understand and optimize their digital marketing efforts.

In growth marketing environments, it's essential to measure, analyze, and improve CAC to ensure sustainable and profitable growth.

In this comprehensive guide, we'll dive into the definition of CAC and its application to e-commerce growth marketing and B2B demand generation.

We'll also discuss specific variables that influence CAC across various marketing channels. 


What is Customer Acquisition Cost (CAC)?

Customer Acquisition Cost (CAC) is the average amount of money spent on acquiring a new customer.

See examples of CAC Calculations →



CAC is calculated by dividing the total marketing and sales expenses by the number of new customers acquired within a specific period. In digital marketing, CAC helps businesses understand the effectiveness of their marketing efforts and the profitability of their customer base.

Why is CAC important?

CAC is vital for several reasons:

  1. Profitability: It helps businesses determine if their marketing efforts are generating a positive return on investment (ROI). A lower CAC means that the company is spending less to acquire new customers, leading to higher profitability.
  2. Budget allocation: By understanding the CAC for different marketing channels and strategies, businesses can allocate their budget more efficiently to maximize ROI.
  3. Performance benchmarking: Comparing CAC across industries and competitors helps businesses identify areas for improvement and set realistic targets.

CAC in E-commerce Growth Marketing

In the e-commerce industry, CAC plays a pivotal role in driving growth and profitability. Online retailers must constantly balance their marketing investments with the revenue generated by new customers.

The following factors can influence CAC in e-commerce:

  1. Marketing channels: Different channels, such as email marketing, social media advertising, and search engine marketing (SEM), can have varying CACs. Understanding which channels deliver the best ROI helps e-commerce businesses optimize their marketing mix.
  2. Product offering: The type of products offered can impact CAC, with higher-priced or niche products potentially requiring more targeted and expensive marketing efforts.
  3. Customer lifetime value (CLV): A higher CLV allows e-commerce businesses to invest more in acquiring new customers while maintaining profitability. By focusing on strategies that increase CLV, such as personalized recommendations and loyalty programs, e-commerce businesses can better justify a higher CAC.

CAC in B2B Demand Generation

For B2B businesses, demand generation is a critical component of their growth strategy. B2B companies typically have longer sales cycles, higher customer lifetime values, and more complex buyer journeys than B2C businesses.

As a result, their approach to CAC differs in the following ways:

  1. Sales and marketing alignment: B2B businesses need to closely align their sales and marketing efforts to ensure consistent messaging and targeting throughout the buyer journey. This alignment can lead to a more efficient sales process and lower CAC.
  2. Content marketing: High-quality content is essential for B2B demand generation, as it helps educate potential customers and build trust. Investing in content marketing can lower CAC by nurturing leads more effectively and reducing the need for costly advertising.
  3. Account-based marketing (ABM): ABM focuses on targeting specific high-value accounts rather than broad-based marketing efforts. This targeted approach can lead to lower CAC as it helps B2B businesses focus their resources on the most promising opportunities.

Variables That Influence CAC in Various Marketing Channels

CAC can vary significantly across different marketing channels due to several factors.

Below, we discuss specific variables that can influence CAC in different marketing channels:

  1. Paid Search Advertising

    • Keyword competition: Highly competitive keywords can drive up the cost-per-click (CPC), leading to a higher CAC. Identifying lower-cost, high-conversion keywords can help optimize CAC.
    • Ad Quality Score: Google AdWords uses the quality score to determine the cost and placement of ads. Higher quality scores lead to lower CPCs and, subsequently, a lower CAC.
    • Landing page optimization: A well-designed landing page with a clear call-to-action can improve conversion rates, reducing CAC.
  2. Social Media Advertising

    • Targeting and audience selection: Precise targeting of the right audience can lead to higher conversion rates and lower CAC.
    • Ad creative and copy: Compelling ad creative and copy can improve click-through rates (CTRs) and conversion rates, leading to a lower CAC.
    • Platform-specific strategies: Each social media platform has its own unique features and user behavior. Adapting strategies to each platform can help optimize CAC.
  3. Email Marketing

    • List quality: A high-quality, engaged email list can lead to higher open rates and conversion rates, lowering CAC.
    • Segmentation and personalization: Sending targeted, personalized emails to specific segments can improve engagement and conversion rates, leading to a lower CAC.
    • Email design and copy: Well-designed emails with compelling copy can boost click-through rates and conversions, reducing CAC.
  4. Content Marketing

    • Content quality and relevance: High-quality, relevant content can attract more organic traffic, increasing conversions and reducing CAC.
    • SEO optimization: Properly optimizing content for search engines can improve search rankings and drive more organic traffic, lowering CAC.
    • Promotion and distribution: Effective content promotion and distribution can increase the reach and visibility of your content, leading to higher conversion rates and a lower CAC.

Simple CAC Calculation: A Basic Example

Calculating CAC in its most basic form is straightforward. Here's a simple example to demonstrate the process:

Suppose you have an e-commerce business that spent $10,000 on marketing in a given month. During that month, you acquired 100 new customers.

The calculation for CAC would be:

CAC = Total marketing spend / Number of new customers

CAC = $10,000 / 100 CAC = $100

In this case, the CAC would be $100 per customer.


This means that, on average, it costs your business $100 to acquire a new customer through your marketing efforts.

Complex, Multi-Channel CAC Calculations: An In-Depth Example

Calculating CAC becomes more complex when considering multiple marketing channels and attributing customer acquisition costs to each channel.

Let's look at a more complex example involving three different marketing channels:

  1. Paid search advertising
  2. Social media advertising
  3. Email marketing

Suppose your e-commerce business spent the following amounts on each channel during a given month:

  1. Paid search advertising: $5,000
  2. Social media advertising: $3,000
  3. Email marketing: $2,000

During that month, your business acquired new customers from each channel as follows:

  1. Paid search advertising: 60 new customers
  2. Social media advertising: 30 new customers
  3. Email marketing: 10 new customers

To calculate the CAC for each channel, you would divide the total spend for each channel by the number of new customers acquired through that channel:

  1. Paid search advertising CAC = $5,000 / 60 = $83.33
  2. Social media advertising CAC = $3,000 / 30 = $100
  3. Email marketing CAC = $2,000 / 10 = $200

With this information, you can determine which marketing channel is most cost-effective for acquiring new customers.

In this case, paid search advertising has the lowest CAC, followed by social media advertising and email marketing.

To calculate the overall CAC across all channels, you would add the total marketing spend and divide it by the total number of new customers:

Overall CAC = ($5,000 + $3,000 + $2,000) / (60 + 30 + 10) = $10,000 / 100 = $100

In this example, the overall CAC is $100 per customer.

How Attribution Models Apply to CAC

When you're analyzing multi-channel CAC, it's essential to consider attribution models.

Attribution models determine how much credit each marketing channel receives for a customer acquisition. There are several attribution models, including:

  1. First touch: 100% of the credit goes to the first marketing touchpoint the customer encountered.
  2. Last touch: 100% of the credit goes to the last marketing touchpoint before the customer converted.
  3. Linear: The credit is divided equally among all touchpoints in the customer journey.
  4. Time decay: More credit is given to touchpoints closer to the conversion event.

Choosing the right attribution model for your business is crucial in accurately understanding the effectiveness of your marketing channels and optimizing your marketing strategy.

Wrapping it all up

Understanding and optimizing Customer Acquisition Cost (CAC) is essential for sustainable growth in digital marketing. By applying the CAC concept to e-commerce growth marketing and B2B demand generation, businesses can make informed decisions about their marketing strategies and budget allocation.

Identifying and addressing variables that influence CAC across various marketing channels can help you improve your ROI and overall profitability.

By continuously monitoring and refining CAC, growth marketing directors can drive long-term success in the competitive digital marketing landscape.

As always, get in touch with us if you need some help navigating!