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Day 8: The Macro Logic of Online Ads & Budget Allocation
| Session Duration: 2 Hours | Phase: 4 — Amplification & Future-Proofing |
Learning Objectives
By the end of this session, students will be able to:
- Explain how the digital advertising auction system determines ad pricing and placement
- Calculate Customer Acquisition Cost (CAC), Return on Ad Spend (ROAS), and Customer Lifetime Value (LTV)
- Determine the maximum viable CAC for a business given its LTV
- Allocate a hypothetical media budget across PPC and organic channels
- Use AI to model multiple financial scenarios for media spend decisions
Hour 1: Strategy & Prompt Design (Instructor-Led — 60 minutes)
8.1 The Paid Media Auction System
When you run a digital ad — on Google, Meta, LinkedIn, or any platform — you are not buying a fixed placement at a fixed price. You are entering a real-time auction that runs every time a user loads a page or opens an app.
Understanding the auction mechanics explains why two businesses in the same industry can pay wildly different prices for the same clicks, and why throwing money at ads without understanding the system produces consistently disappointing results.
How the Google Ads Auction Works
Every time a user searches on Google:
- Google identifies all ads eligible to appear for that search query
- Each eligible advertiser’s Ad Rank is calculated
- The top Ad Ranks win placement. The advertiser in position 1 pays the minimum required to maintain that position, not their maximum bid.
Ad Rank Formula:
Ad Rank = Bid Amount × Quality Score × Context Factors
Quality Score (1–10) is Google’s estimate of how relevant and useful your ad and landing page are to the user. It has three components:
| Component | Weight | What It Measures |
|---|---|---|
| Expected CTR | ~35% | How likely users are to click your ad |
| Ad Relevance | ~32% | How closely your ad matches the search intent |
| Landing Page Experience | ~33% | How useful and relevant your page is to users who click |
The counterintuitive insight: A higher Quality Score reduces your cost per click. An advertiser with a Quality Score of 9 can pay LESS than a competitor with a Quality Score of 3 and still outrank them. This is Google’s incentive mechanism to improve the quality of the ads ecosystem.
The Meta Ads Auction (Facebook/Instagram)
The Meta auction works similarly but uses different targeting inputs:
Ad Rank = Bid × Estimated Action Rate × Ad Quality
- Bid: Your maximum bid or your target cost
- Estimated Action Rate: Meta’s prediction of how likely a given user is to take the action you want (click, purchase, video view)
- Ad Quality: User feedback signals — are people hiding, skipping, or reporting your ad?
Key difference from Google: Meta’s targeting is interest and behaviour-based, not keyword-based. You are targeting a profile of person rather than a specific search query. This means Meta is better for building awareness with audiences who don’t yet know they need your product, while Google captures existing demand from people actively searching for it.
8.2 Financial Unit Economics: The Manager’s Toolkit
Unit economics refers to the financial metrics that describe the revenue and cost associated with a single unit of business — typically one customer. Without understanding unit economics, you cannot make rational decisions about how much to spend on advertising.
Customer Acquisition Cost (CAC)
CAC is the total cost of convincing one new customer to buy.
Formula:
CAC = Total Marketing & Sales Spend ÷ Number of New Customers Acquired
Example: If you spent NPR 150,000 on marketing in September (ads, agency fees, tools) and acquired 50 new customers, your CAC = NPR 3,000.
Blended vs. Channel-Level CAC
The formula above gives you “blended CAC” — the average across all channels. Smart managers also calculate channel-level CAC:
- Google Ads CAC: NPR 4,500 (high quality leads, higher cost)
- Facebook Ads CAC: NPR 2,200 (lower quality leads, lower cost)
- Organic SEO CAC: NPR 800 (higher effort, lowest cost per customer)
This breakdown reveals where to invest the next marginal rupee of marketing spend.
Customer Lifetime Value (LTV / CLV)
LTV is the total revenue a customer generates over their entire relationship with your business.
Simple LTV Formula:
LTV = Average Order Value × Purchase Frequency × Average Customer Lifespan
Example:
- Average Order Value: NPR 2,500
- Purchase Frequency: 4 times per year
- Average Customer Lifespan: 2.5 years
- LTV = NPR 2,500 × 4 × 2.5 = NPR 25,000
The LTV:CAC Ratio — The Most Important Business Metric
LTV:CAC Ratio = LTV ÷ CAC
| Ratio | Interpretation |
|---|---|
| < 1:1 | You are losing money on every customer acquired. Immediate action needed. |
| 1:1 to 2:1 | You are breaking even or barely profitable. Not viable long-term. |
| 3:1 | The gold standard. Healthy, scalable business. |
| 4:1+ | Consider investing more aggressively in acquisition. |
In the example above: LTV NPR 25,000 ÷ CAC NPR 3,000 = 8.3:1 ratio — exceptional. This business can afford to spend much more on acquisition.
Return on Ad Spend (ROAS)
ROAS measures the revenue generated per rupee spent on advertising (not accounting for costs or margins).
Formula: ROAS = Revenue from Ads ÷ Ad Spend
Example: NPR 500,000 revenue from NPR 100,000 ad spend = 5x ROAS (often expressed as “5 ROAS” or “500%”)
The Breakeven ROAS Formula:
Breakeven ROAS = 1 ÷ Gross Margin %
Example: If your gross margin is 40%, your breakeven ROAS is 1 ÷ 0.40 = 2.5x. Any ROAS below 2.5x means you are losing money even if your revenue looks impressive.
This is why a business with 10% gross margins needs a 10x ROAS to break even — and why understanding margins before running ads is non-negotiable.
8.3 Budget Allocation Strategy: SEO vs. Paid
The eternal debate: should you invest in organic (SEO, content) or paid advertising? The answer is always: both, in the right proportions, at the right stage of business maturity.
The Investment Timeline Comparison
| Dimension | Paid Advertising | Organic SEO |
|---|---|---|
| Time to results | Immediate (hours/days) | Long-term (3–12 months) |
| What stops when budget stops | All traffic stops | Nothing — it compounds |
| Predictability | High (you set the spend) | Low (algorithm-dependent) |
| Targeting precision | Very high | Limited |
| Cost per acquisition over time | Stays constant or increases | Decreases as authority builds |
| Best use | Immediate revenue, testing, launches | Long-term authority, compounding growth |
The Portfolio Approach
Most mature digital businesses run a portfolio of both, typically:
- New business (0–6 months): 80% paid, 20% organic — need immediate revenue
- Growth stage (6–18 months): 60% paid, 40% organic — building authority while maintaining revenue
- Mature business (18+ months): 40% paid, 60% organic — organic compounds; paid used for specific campaigns and launches
Hour 2: Digital Sandbox Lab (Individual Execution — 60 minutes)
The AI Prompting Framework: The Marketing Budget Scenario Simulator
This prompt uses AI as a financial modelling assistant to test different budget allocation scenarios before committing real money.
The Full Prompt Template
You are a digital marketing strategist and financial modeller
with expertise in paid media and organic growth planning.
My business details:
- Business type: [e.g., e-commerce, service, SaaS]
- Average Order Value (AOV): NPR [amount]
- Gross margin: [%]
- Average purchase frequency (times/year): [number]
- Average customer lifespan (years): [number]
- Current monthly revenue: NPR [amount] (or "pre-launch")
- Available monthly marketing budget: NPR [amount]
- Current organic traffic per month: [number] (or "0" for new site)
TASK 1: UNIT ECONOMICS CALCULATION
Calculate the following for my business:
- Customer Lifetime Value (LTV)
- Maximum viable CAC (at 3:1 LTV:CAC ratio)
- Breakeven ROAS (given my gross margin)
- Profit contribution per customer at maximum viable CAC
TASK 2: BUDGET ALLOCATION SCENARIOS
Model 3 different monthly budget allocation scenarios for
my NPR [budget] per month. For each scenario:
Scenario A: Paid-Heavy (80% paid / 20% content/organic)
Scenario B: Balanced (50% paid / 50% content/organic)
Scenario C: Organic-Heavy (20% paid / 80% content/organic)
For each scenario, show:
- Exact NPR allocation per channel
- Estimated monthly traffic (paid + organic)
- Estimated conversion rate and customer acquisitions
- Estimated monthly revenue
- Estimated CAC
- LTV:CAC ratio
- Months to 3:1 LTV:CAC (if not already there)
- Risk level and key assumption
Format as a comparison table.
TASK 3: SENSITIVITY ANALYSIS
For Scenario B (balanced), model what happens when:
a) Landing page conversion rate doubles (e.g., from 2% to 4%)
b) CPC increases by 40% (rising competition)
c) AOV increases by 25% (better offer architecture)
Show the impact on CAC, ROAS, and monthly profit for each.
TASK 4: 90-DAY MEDIA PLAN OUTLINE
Based on the recommended scenario, provide a month-by-month
outline for the first 3 months:
- Month 1: What to prioritise and why
- Month 2: Optimisation focus
- Month 3: Scale decisions
Include specific metrics to hit before advancing to the next phase.
Step-by-Step Lab Instructions
⚙️ Setup (5 minutes)
- Open your AI tool in a new conversation
- Create a new Google Sheet:
[Business Name] — Media Budget Model - Add tabs: “Unit Economics” / “Scenario Comparison” / “90-Day Plan”
📊 Part 1: Define Your Financial Parameters (15 minutes)
Before running the AI simulation, you need plausible financial parameters for your mock business. Use industry benchmarks to make yours realistic:
Research activity: Search for “[your industry] average order value” and “[your industry] gross margin” to find realistic benchmarks. For example:
- Handmade e-commerce: AOV NPR 2,500–5,000, Gross margin 55–70%
- Service business: AOV NPR 15,000–50,000, Gross margin 60–80%
- SaaS: AOV NPR 800/month, Gross margin 70–85%
Fill in the Unit Economics Worksheet below before running the AI prompt.
🤖 Part 2: Run the Budget Scenario Simulator (25 minutes)
- Fill in all financial parameters in the prompt
- Run the full scenario comparison
- Copy the comparison table into your Google Sheet “Scenario Comparison” tab
- Identify which scenario you would recommend for your business and document your reasoning
✏️ Part 3: Build Your 90-Day Media Plan (15 minutes) Using the 90-Day Media Plan Template below:
- Choose your recommended budget scenario
- Allocate spend across specific channels (Google Search / Meta / LinkedIn / Content)
- Set success metrics for each month
- Define the decision point: what would trigger you to increase budget? Decrease? Shift channels?
Templates & Worksheets
Template 1: Unit Economics Worksheet
UNIT ECONOMICS CALCULATOR
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Business: _______________________________
INPUTS
Average Order Value (AOV): NPR _________
Gross Margin: _________%
Purchase Frequency (times/year): _______
Customer Lifespan (years): _____________
Monthly Marketing Spend: NPR ___________
Monthly New Customers Acquired: ________
CALCULATED METRICS
Customer Lifetime Value (LTV):
LTV = AOV × Frequency × Lifespan
= NPR _____ × _____ × _____ = NPR _____
Customer Acquisition Cost (CAC):
CAC = Monthly Spend ÷ Monthly New Customers
= NPR _____ ÷ _____ = NPR _____
LTV:CAC Ratio:
= LTV ÷ CAC = _____ : 1
Healthy target: 3:1 or above
Maximum Viable CAC (at 3:1 ratio):
= LTV ÷ 3 = NPR _____
Breakeven ROAS:
= 1 ÷ Gross Margin% = _____x
(Need at least _____x ROAS to break even)
Current ROAS (if applicable):
= Revenue ÷ Ad Spend = _____x
INTERPRETATION
Current LTV:CAC status: [ ] Below 3:1 [ ] At 3:1 [ ] Above 3:1
Current ROAS status: [ ] Below breakeven [ ] Above breakeven
Recommended action: ____________________
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Template 2: 90-Day Media Budget Plan
90-DAY MEDIA BUDGET PLAN
━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
Business: _______________________________
Total Monthly Budget: NPR _______________
Chosen Scenario: ________________________
BUDGET ALLOCATION
Google Search Ads: NPR _________ (___ %)
Meta Ads (FB/IG): NPR _________ (___ %)
LinkedIn Ads: NPR _________ (___ %)
Content / SEO: NPR _________ (___ %)
Tools / Software: NPR _________ (___ %)
TOTAL: NPR _________ (100%)
MONTH 1: BUILD & TEST
Primary Focus: _________________________
Success Metrics:
- CAC target: Below NPR _____________
- Conversions target: _______________
- ROAS target: _____________________
Experiments to Run:
1. ___________________________________
2. ___________________________________
Decision Point: If [metric] is [threshold]
by Day 30, I will [action].
MONTH 2: OPTIMISE
Primary Focus: _________________________
Based on Month 1 data, shift budget:
Increase: ___________ by NPR _________
Decrease: ___________ by NPR _________
Reason: ________________________________
Success Metrics:
- CAC target: Below NPR _____________
- ROAS target: _____________________
MONTH 3: SCALE
Primary Focus: _________________________
Scale Trigger: Scale when [metric] reaches [target].
Success Metrics:
- Revenue target: NPR ________________
- LTV:CAC target: ___________________
REVIEW DATE: ___________________________
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Resources & Further Reading
🛠️ Tools Required Today
| Tool | Purpose | Cost |
|---|---|---|
| Google Ads (learning mode) | Understand auction mechanics | Free to browse |
| Google Keyword Planner | CPC estimates for budget modelling | Free |
| Meta Ads Manager (learning mode) | Audience size and CPM estimates | Free to browse |
| Google Sheets | Financial modelling | Free |
| ChatGPT / Claude | Budget scenario simulation | Free |
📚 Reference Reading
- Perry Marshall — Ultimate Guide to Google AdWords — Best practical guide to the Google auction system
- The CMO Survey — cmosurvey.org — Annual data on marketing budget allocations by industry
- WordStream PPC Benchmarks — Industry average CPC, CTR, and conversion rate data by vertical
- Profitwell Blog — profitwell.com/recur/all — Outstanding data-driven articles on unit economics
📊 Industry Benchmarks: Nepal Digital Advertising (2024 estimates)
| Platform | Avg CPC | Avg CPM | Avg Conversion Rate |
|---|---|---|---|
| Google Search | NPR 15–80 | — | 3–5% |
| Google Display | NPR 2–8 | NPR 80–250 | 0.5–1% |
| NPR 5–30 | NPR 50–200 | 0.8–1.5% | |
| NPR 8–40 | NPR 80–300 | 1–2% | |
| NPR 80–400 | NPR 400–1,200 | 2–4% |
Note: Nepali market CPCs are significantly lower than US/EU markets. International benchmarks typically show Google Search CPCs of USD 2–10 for competitive industries.
Key Takeaways
- The Auction Rewards Quality — A high Quality Score / Ad Relevance Score lowers your costs. Invest in better creatives and landing pages, not just higher bids.
- LTV:CAC is the North Star — At 3:1 you have a healthy business. Below 1:1 you have a money-losing marketing machine.
- Know Your Breakeven ROAS Before Spending — If your margins are 30%, you need 3.3x ROAS to break even. Many businesses discover this too late.
- Paid and Organic Are Complements, Not Competitors — Paid funds short-term growth while organic builds long-term equity.
- Model Before You Spend — The AI budget simulator is a tool to avoid expensive real-world experiments. Use it.
| *Previous: Day 7 – Email Marketing & Retention ← | Next: Day 9 – Meta Ads Manager & Creative Control →* |
