Entrepreneurship Grade 9: Unit Economics CAC LTV Burn Rate

Study Guide: Unit Economics – CAC, LTV, Burn Rate Grade 9 | Entrepreneurship

1. The Driving Question

"If you spend $500 on Instagram ads to get 100 new customers, but each customer only pays you $3 once, are you actually making money—or just burning cash? How do you know when your business is sustainable, not just surviving on hope and hype?"

2. The Core Idea – Built, Not Listed

Imagine you’re running a lemonade stand in your neighborhood, but instead of just selling cups, you’re trying to turn it into a real business. You decide to spend $20 on flyers to attract new customers. The flyers work—10 new people buy lemonade that week. But here’s the catch: each customer only buys one $2 cup. That means you spent $20 to make $20. Worse, some of those customers never come back. Now you’re stuck in a cycle: spend money to get customers, but the customers don’t stick around long enough to cover the cost.

This is where unit economics comes in. It’s the math that tells you whether each customer is worth more than what you spent to get them. If you’re losing money on every sale, no amount of "growth" will save you. But if each customer brings in more than they cost, your business can scale without running out of cash.

Key Vocabulary: - Customer Acquisition Cost (CAC): Definition: The total cost of convincing a customer to buy your product, including marketing, sales, and any other expenses. Example: If you spend $100 on TikTok ads and get 50 new subscribers to your online tutoring service, your CAC is $2 per customer. College Note: In advanced finance, CAC is often broken into "blended" (all customers) and "paid" (only customers from paid ads), and it’s adjusted for customer churn over time.

• Lifetime Value (LTV): Definition: The average amount of money a customer will spend on your product or service over the entire time they’re a customer. Example: A gym member pays $30/month and stays for 2 years. Their LTV is $720, even if they only pay $30 upfront. College Note: LTV models in data science use predictive analytics to estimate future behavior, not just historical averages.

• Burn Rate: Definition: How much money your business loses each month before it starts making a profit. Example: If your lemonade stand makes $100 in sales but spends $150 on lemons, cups, and flyers, your burn rate is $50/month. College Note: In venture capital, burn rate is often expressed as "runway"—how many months you can operate before running out of cash.

• Unit Economics: Definition: The direct revenues and costs associated with a single unit of your business (e.g., one customer, one product). Example: For a meal-kit delivery service, the unit economics would calculate the cost of ingredients, packaging, and delivery for one box vs. the price the customer pays. College Note: In economics, this is called "marginal analysis"—studying the cost and benefit of one additional unit.

3. Assessment Translation

How This Appears on Assessments: - Classroom: Short case studies (e.g., "A startup spends $1,000 on ads and gets 200 customers. Each customer pays $10/month and stays for 6 months. Calculate CAC and LTV. Is this business sustainable?"). - Standardized Tests (e.g., DECA, FBLA): Multiple-choice questions with distractors like: - Distractor 1: Confusing CAC with total revenue (e.g., "CAC is $10 because the customer paid $10"). - Distractor 2: Ignoring time in LTV (e.g., "LTV is $10 because that’s what they paid today"). - Distractor 3: Misapplying burn rate (e.g., "Burn rate is $500 because that’s the startup’s total expenses"). - SAT/ACT (if math-heavy): Word problems testing ratio/proportion skills (e.g., "If a company’s LTV:CAC ratio is 3:1, and their CAC is $15, what is their LTV?").

Proficient vs. Developing Responses: | Proficient | Developing | |----------------|----------------| | "The CAC is $5 ($1,000 ÷ 200 customers). The LTV is $60 ($10/month × 6 months). The LTV:CAC ratio is 12:1, which is healthy because it’s above 3:1. The business is sustainable." | "The CAC is $1,000. The LTV is $10. The business is good." (Ignores per-customer math, doesn’t compare LTV to CAC.) | | Shows all calculations, explains the ratio, and draws a conclusion. | Missing steps, no comparison, or incorrect units. |

Model Proficient Response: "To find CAC, divide total ad spend by new customers: $1,000 ÷ 200 = $5 per customer. For LTV, multiply monthly revenue by customer lifespan: $10 × 6 = $60. The LTV:CAC ratio is 60:5, or 12:1. This is strong because investors usually look for at least 3:1. The business is sustainable because each customer brings in 12x what it cost to acquire them."

4. Mistake Taxonomy

Mistake 1: Ignoring Time in LTV - Prompt: "A subscription box costs $20/month. What is the LTV of a customer who signs up today?" - Common Wrong Answer: "$20." - Why It Loses Credit: LTV is about the lifetime value, not a single purchase. The student ignored how long the customer stays. - Correct Approach: Ask: "How many months does the average customer stay?" If it’s 12 months, LTV = $20 × 12 = $240.

Mistake 2: Confusing CAC with Total Marketing Spend - Prompt: "A company spends $5,000 on ads and gets 500 customers. What is their CAC?" - Common Wrong Answer: "$5,000." - Why It Loses Credit: CAC is per customer. The student didn’t divide by the number of customers. - Correct Approach: CAC = Total spend ÷ Number of customers = $5,000 ÷ 500 = $10.

Mistake 3: Misapplying Burn Rate to Profit - Prompt: "A startup has $50,000 in the bank. They spend $10,000/month and make $8,000/month in revenue. What is their burn rate?" - Common Wrong Answer: "$2,000 (because $10,000 - $8,000 = $2,000)." - Why It Loses Credit: Burn rate is about cash outflow, not profit. The student subtracted revenue, which isn’t part of the definition. - Correct Approach: Burn rate = Total monthly expenses = $10,000. (Revenue is irrelevant for burn rate—it’s about how fast you’re spending cash.)

5. Connection Layer

1. Within Entrepreneurship-Pricing Strategies: Understanding LTV helps you decide how much to charge. If your LTV is low, you might need to raise prices or upsell customers (e.g., a $10/month app adding a $5 premium tier).

2. Across Subjects-Statistics (Math): LTV and CAC are averages, but real data is messy. In stats, you’d use standard deviation to see how much customer behavior varies—some customers stay for years, others leave after a month.

3. Outside School-Freelancing/Gig Work: If you’re a tutor charging $30/hour, your "CAC" is the time you spend marketing (e.g., posting on Nextdoor). Your "LTV" is how many hours a student books. If you spend 2 hours finding a student who only books 1 hour, you’re losing money.

6. The Stretch Question

"If a startup’s LTV:CAC ratio is 5:1, but their burn rate is $100,000/month and they only have $500,000 in the bank, are they in trouble? Why or why not?"

Pointer Toward the Answer: A 5:1 ratio is strong—each dollar spent on ads brings in $5 over time. But burn rate is about cash flow. If they’re spending $100K/month and only making $20K/month in profit (because LTV takes time to realize), they’ll run out of cash in 5 months. The question is whether they can survive long enough for LTV to kick in. Investors might still fund them if they believe in the long-term math, but the startup needs to either cut costs or raise more money fast.