Glossary / metrics

CAC (Customer Acquisition Cost)

metrics

Quick Definition

CAC is the total cost of acquiring one new customer, including marketing, sales, and advertising expenses. Formula: Total Sales & Marketing Spend ÷ Number of New Customers Acquired.

Detailed Explanation

Customer Acquisition Cost is one of the most critical SaaS metrics. It tells you how much you spend to convince one person to become a paying customer. Calculate it: Add all sales and marketing expenses (ads, salaries, tools, events) in a period, divide by new customers acquired in that period. Example: Spent ₹10 lakhs on marketing in Q1, got 100 customers → CAC = ₹10,000 per customer. CAC must be compared with LTV (Lifetime Value). Rule of thumb: LTV should be 3x CAC minimum. If CAC is ₹10K, LTV should be ₹30K+ for healthy business. CAC varies by channel: Organic/SEO (₹500-₹2K), Paid ads (₹5K-₹20K), Enterprise sales (₹50K-₹5L). CAC payback period matters too: How long to recover acquisition cost from customer payments? Best: <6 months. Acceptable: 6-12 months. Danger: >18 months. High CAC kills startups—you run out of money before customers become profitable. Optimize CAC through: better targeting, conversion rate optimization, referral programs, content marketing, product-led growth.

Formula

CAC = (Total Sales + Marketing Spend) ÷ Number of New Customers

Real-World Examples

Dropbox

Reduced CAC from $233 to $70 through referral program ("Get 500MB free for every friend"). Viral growth replaced paid ads.

Typical B2B SaaS

Spends ₹20L/month on ads + ₹15L on sales team (2 people) = ₹35L. Acquires 50 customers/month → CAC = ₹70,000. If LTV is ₹3L, healthy 4.3x ratio.

Failed startup

CAC was ₹15K, LTV only ₹10K (negative unit economics). Every customer LOST ₹5K. Burned through funding, shut down despite growth.

Why It Matters for Your Startup

CAC > LTV means you lose money on every customer. Unsustainable. CAC determines how fast you can grow—lower CAC = more customers with same budget. Investors scrutinize CAC:LTV ratio heavily. Below 3:1 is red flag.

Common Mistakes

  • Not tracking CAC at all (flying blind on profitability)
  • Calculating CAC without including salaries (massively underestimating)
  • Comparing CAC across different customer segments (enterprise vs SMB have different CACs)
  • Ignoring CAC payback period (12-month payback ties up too much cash)
  • Scaling marketing before optimizing CAC (burning money inefficiently)

Frequently Asked Questions

What is a good CAC for SaaS?

CAC should be 3x less than LTV. If your annual subscription is ₹12K and customers stay 3 years, LTV = ₹36K. CAC should be ₹12K or less.

Should I include founder salaries in CAC?

If founder is doing sales/marketing, yes include their opportunity cost. If bootstrapped and taking no salary, you can exclude but note this in reporting.

How to reduce CAC?

Improve conversion rates, add referral programs, focus on organic/SEO, optimize ad targeting, implement product-led growth, increase word-of-mouth.

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CAC (Customer Acquisition Cost) - Definition, Examples & Formula | StartupIdeasDB Glossary | startupideasdb.com