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Customer Acquisition Cost (CAC)

Definition

Customer Acquisition Cost (CAC) refers to the total cost incurred by a company to acquire a new customer. It includes marketing, sales, and other related expenses used to attract and convert a lead into a paying customer.

Description

Customer Acquisition Cost (CAC) measures how much it costs to acquire a new customer — across paid media, sales efforts, campaigns, tools, and everything in between. It’s a core signal of growth efficiency and marketing ROI.

The relevance and interpretation of this metric shift depending on the model or product:

  • In PLG, it reflects self-serve CAC vs. assisted CAC
  • In B2B SaaS, it includes outbound, SDR, and marketing attribution
  • In eCommerce, it helps balance discounting vs. LTV

A rising CAC may flag channel fatigue or targeting inefficiency. A declining CAC suggests cost-effective growth — as long as customer quality holds. Segment by channel, campaign, or acquisition path to tune your GTM mix.

Customer Acquisition Cost informs:

  • Strategic decisions, like budget allocation or CAC:LTV optimization
  • Tactical actions, such as audience pruning or bid strategy tweaks
  • Operational improvements, including CRM cleanup or lead routing
  • Cross-functional alignment, by aligning finance, marketing, and product teams on efficient, scalable acquisition

Key Drivers

These are the main factors that directly impact the metric. Understanding these lets you know what levers you can pull to improve the outcome

  • Channel Efficiency and Source Mix: CAC rises when budget is weighted toward high-cost channels (e.g., outbound, paid search) without balancing low-cost levers like referrals or SEO.
  • Sales Cycle Length and Complexity: Long, high-touch sales processes inflate CAC. PLG or short-funnel models reduce it.
  • Conversion Rates at Each Funnel Stage: Poor conversion between MQL, SQL, and Closed-Won means you’re paying more per customer.

Improvement Tactics & Quick Wins

Actionable ideas to optimize this KPI, from fast, low-effort wins to strategic initiatives that drive measurable impact.

  • If CAC is too high, rebalance toward lower-CAC sources like referrals, content, or freemium signups.
  • Add qualification filters early (e.g., job title, industry) to reduce wasted MQL spend.
  • Run a test removing friction in the demo request → booking → sales call handoff process.
  • Refine nurture sequences and remarketing to improve funnel progression efficiency.
  • Partner with RevOps to calculate CAC by segment, source, and deal type — and cut the losers.

  • Required Datapoints to calculate the metric


    • Total Marketing and Sales Costs: Includes advertising spend, sales commissions, software costs, staff salaries, etc.
    • Total Number of New Customers Acquired: The total number of customers gained in the given time frame.
  • Example to show how the metric is derived


    A subscription-based software company calculates its CAC for Q1:

    • Total Acquisition Costs: $100,000
    • Number of Customers Acquired: 500
    • CAC = $100,000 / 500 = $200 per customer

Formula

Formula

\[ \mathrm{Customer\ Acquisition\ Cost} = \frac{\mathrm{Total\ Marketing\ and\ Sales\ Costs}}{\mathrm{Total\ Number\ of\ New\ Customers\ Acquired}} \]

Data Model Definition

How this KPI is structured in Cube.js, including its key measures, dimensions, and calculation logic for consistent reporting.

cube('MarketingAndSalesCosts', {
  sql: `SELECT * FROM marketing_and_sales_costs`,
  measures: {
    totalCost: {
      sql: `total_cost`,
      type: 'sum',
      title: 'Total Marketing and Sales Costs',
      description: 'Total costs incurred for marketing and sales activities.'
    }
  },
  dimensions: {
    id: {
      sql: `id`,
      type: 'number',
      primaryKey: true
    },
    createdAt: {
      sql: `created_at`,
      type: 'time',
      title: 'Created At',
      description: 'The time when the cost record was created.'
    }
  }
})
cube('NewCustomers', {
  sql: `SELECT * FROM new_customers`,
  measures: {
    totalNewCustomers: {
      sql: `customer_id`,
      type: 'countDistinct',
      title: 'Total Number of New Customers Acquired',
      description: 'The total number of new customers acquired in the given time frame.'
    }
  },
  dimensions: {
    id: {
      sql: `id`,
      type: 'number',
      primaryKey: true
    },
    acquiredAt: {
      sql: `acquired_at`,
      type: 'time',
      title: 'Acquired At',
      description: 'The time when the customer was acquired.'
    }
  }
})
cube('CustomerAcquisitionCost', {
  sql: `SELECT * FROM customer_acquisition_cost`,
  measures: {
    customerAcquisitionCost: {
      sql: `${MarketingAndSalesCosts.totalCost} / NULLIF(${NewCustomers.totalNewCustomers}, 0)`,
      type: 'number',
      title: 'Customer Acquisition Cost',
      description: 'The average cost incurred to acquire a new customer.'
    }
  },
  joins: {
    MarketingAndSalesCosts: {
      relationship: 'belongsTo',
      sql: `${CUBE}.marketing_sales_cost_id = ${MarketingAndSalesCosts.id}`
    },
    NewCustomers: {
      relationship: 'belongsTo',
      sql: `${CUBE}.new_customer_id = ${NewCustomers.id}`
    }
  },
  dimensions: {
    id: {
      sql: `id`,
      type: 'number',
      primaryKey: true
    },
    calculationDate: {
      sql: `calculation_date`,
      type: 'time',
      title: 'Calculation Date',
      description: 'The date when the customer acquisition cost was calculated.'
    }
  }
})

Note: This is a reference implementation and should be used as a starting point. You’ll need to adapt it to match your own data model and schema


Positive & Negative Influences

  • Negative influences


    Factors that drive the metric in an undesirable direction, often signaling risk or decline.

    • Channel Efficiency and Source Mix: When the budget is heavily allocated to high-cost channels such as outbound marketing and paid search, the Customer Acquisition Cost increases due to the higher expenses associated with these channels.
    • Sales Cycle Length and Complexity: A lengthy and complex sales cycle requires more resources and time, leading to an increase in Customer Acquisition Cost as more effort is needed to convert a lead into a customer.
    • Poor Conversion Rates at Each Funnel Stage: Low conversion rates between Marketing Qualified Leads (MQL), Sales Qualified Leads (SQL), and Closed-Won stages result in higher Customer Acquisition Cost because more investment is needed to achieve the same number of customers.
    • Inefficient Targeting: Spending resources on poorly targeted audiences increases Customer Acquisition Cost as it leads to lower conversion rates and higher costs per acquisition.
    • High Customer Churn Rate: A high churn rate necessitates acquiring more new customers to maintain growth, thereby increasing the Customer Acquisition Cost.
  • Positive influences


    Factors that push the metric in a favorable direction, supporting growth or improvement.

    • Effective Channel Mix: Utilizing a balanced mix of low-cost channels such as referrals and SEO can decrease Customer Acquisition Cost by reducing the overall spend needed to acquire new customers.
    • Short Sales Cycle: Implementing a Product-Led Growth (PLG) model or other strategies that shorten the sales cycle can reduce Customer Acquisition Cost by minimizing the resources and time required to convert leads.
    • High Conversion Rates at Each Funnel Stage: Improving conversion rates between MQL, SQL, and Closed-Won stages decreases Customer Acquisition Cost as fewer resources are needed to convert leads into customers.
    • Strong Brand Recognition: A well-recognized brand can lower Customer Acquisition Cost by increasing organic traffic and conversion rates, reducing the need for expensive marketing efforts.
    • Customer Referral Programs: Implementing effective referral programs can significantly reduce Customer Acquisition Cost by leveraging existing customers to acquire new ones at a lower cost.

Involved Roles & Activities


Funnel Stage & Type

  • AAARRR Funnel Stage


    This KPI is associated with the following stages in the AAARRR (Pirate Metrics) funnel:

    Acquisition

  • Type


    This KPI is classified as a Lagging Indicator. It reflects the results of past actions or behaviors and is used to validate performance or assess the impact of previous strategies.


Supporting Leading & Lagging Metrics

  • Leading


    These leading indicators influence this KPI and act as early signals that forecast future changes in this KPI.

    • Product Qualified Leads: Product Qualified Leads (PQLs) are a strong leading indicator for Customer Acquisition Cost (CAC) because they represent users who have demonstrated high intent and product engagement. A higher volume and quality of PQLs can forecast more efficient conversions, potentially lowering CAC by enabling sales teams to focus on high-probability prospects.
    • Trial-to-Paid Conversion Rate: This metric reflects how effectively free trial users convert into paying customers. A strong trial-to-paid conversion rate signals that top-of-funnel and onboarding investments are efficiently generating new customers, helping to reduce or control CAC by improving conversion efficiency.
    • Marketing Qualified Leads (MQLs): MQLs are a key precursor to customer acquisition. An increase in high-quality MQLs generally predicts future increases in customer acquisition, and tracking their cost and conversion can provide early signals of CAC trends.
    • Activation Rate: A high activation rate indicates that a greater proportion of new users are reaching meaningful value milestones, which increases downstream conversion efficiency and can lower total acquisition costs by maximizing funnel effectiveness.
    • Deal Velocity: Deal Velocity measures the speed at which prospects move through the sales funnel. Faster deal cycles typically reduce sales costs and resource allocation per customer, exerting downward pressure on CAC and serving as an early signal of acquisition efficiency.
  • Lagging


    These lagging indicators confirm, quantify, or amplify this KPI and help explain the broader business impact on this KPI after the fact.

    • Cost per Acquisition: Cost per Acquisition (CPA) is a direct component of CAC, often used interchangeably in many organizations. It quantifies the average spend to acquire a customer and is a lagging measure confirming if acquisition strategies are cost-effective or driving up CAC.
    • Conversion Rate: The overall conversion rate from lead to customer quantifies how efficiently the funnel turns prospects into paying customers. Low or declining conversion rates can increase CAC, while improvements can amplify acquisition efficiency, making this metric a key lagging amplifier of CAC.
    • Average Sales Cycle Length: A longer sales cycle increases the resources and time required to close deals, driving up CAC. This lagging KPI quantifies the impact of sales process efficiency (or lack thereof) on acquisition costs.
    • Cost to Serve: Cost to Serve measures the operational expenses directly tied to servicing new customers. If these costs rise, they inflate the overall acquisition cost, making this a confirming and quantifying KPI for CAC.
    • Customer Churn Rate: While churn is typically seen as a retention metric, high churn can retroactively increase CAC because more new customers must be acquired to replace lost ones, leading to higher acquisition investments and reduced overall efficiency.