Market Sizing
For unfamiliar placeholders or connected tools, see CONNECTORS.md.
TAM (Total Addressable Market), SAM (Serviceable Available Market), SOM (Serviceable Obtainable Market) analysis framework. Cross-validates using 3 methodologies (Top-down, Bottom-up, Value Theory) to present compelling market opportunity to investors.
How It Works
┌─────────────────────────────────────────────────────────────────┐
│ MARKET SIZING FRAMEWORK │
├─────────────────────────────────────────────────────────────────┤
│ Core Features (Standalone) │
│ ✓ Calculate TAM/SAM/SOM using 3 methodologies │
│ ✓ Web search for industry reports and market data │
│ ✓ Cross-validate with triangulation for confidence │
│ ✓ Create investor-ready visual summary & assumptions doc │
├─────────────────────────────────────────────────────────────────┤
│ Enhanced Mode (with tool connections) │
│ + ~~knowledge base: Refine Bottom-up with internal customer │
│ data │
│ + ~~spreadsheet: Model market size scenarios │
│ + ~~data enrichment: Validate against competitor data │
└─────────────────────────────────────────────────────────────────┘
Getting Started
- Basic Analysis: "Analyze TAM/SAM/SOM for Korea B2B SaaS CRM"
- Specific Segment: "What's the market size for SMB accounting SaaS?"
- Investor Pitch: "Create a market sizing slide for Series A pitch"
- Validate: "Verify our $5B TAM estimate"
TAM / SAM / SOM Definition
3-Tier Framework
┌──────────────────────────────────────────────────────┐
│ TAM (Total) │
│ "Everyone with this problem" │
│ Example: Global CRM market $50B │
│ ┌───────────────────────────────────────────┐ │
│ │ SAM (Serviceable) │ │
│ │ "People we can reach" │ │
│ │ Example: Korea SMB CRM $500M │ │
│ │ ┌─────────────────────────────────┐ │ │
│ │ │ SOM (Obtainable) │ │ │
│ │ │ "Realistic capture target" │ │ │
│ │ │ Example: 3-year goal $15M (3%) │ │ │
│ │ └─────────────────────────────────┘ │ │
│ └───────────────────────────────────────────┘ │
└──────────────────────────────────────────────────────┘
Each Tier Defined
| Tier |
Definition |
Key Question |
Investor Focus |
| TAM |
Total addressable market |
"If all potential customers used us?" |
Is market big enough? ($1B+ preferred) |
| SAM |
Serviceable available market |
"Who can our business model reach?" |
Is target realistic? |
| SOM |
Serviceable obtainable market |
"How much can we realistically capture?" |
Is execution feasible? |
Typical Ratios
- SAM: 10-50% of TAM (geography, segment, channel constraints)
- SOM: 2-10% of SAM (3-5 year goal, competition considered)
Example (Global SaaS CRM):
- TAM: $50B (all enterprises worldwide)
- SAM: $5B (Korea + SMB + cloud-based)
- SOM: $150M (5-year 3% market share goal)
3 Methodologies
Methodology Comparison
| Methodology |
Approach |
Advantages |
Disadvantages |
Best For |
| Top-down |
Market → Segment |
Fast, uses reports |
Many assumptions, over-estimates |
Mature market, initial estimates |
| Bottom-up |
Unit economics → Aggregate |
Accurate, realistic |
Data-heavy, time-consuming |
Validated Unit Economics |
| Value Theory |
Customer value creation |
Fits new markets, differentiates |
Subjective, hard to prove |
New categories, 10x products |
Recommendation: Execute all 3, then cross-validate (Triangulation)
1. Top-down (Top to Bottom)
Process
Entire market size
↓ Region filter (example: Korea = 2% of global)
Korea market size
↓ Segment filter (example: SMB = 60%)
Target segment
↓ Adoption rate (example: cloud conversion = 40%)
SAM
↓ Market share target (example: 5% in 5 years)
SOM
Calculation Example (CRM SaaS)
- TAM: Global CRM market = $50B (Gartner 2024)
- Region Filter: Korea = 2% of global = $1B
- Segment: SMB (10-500 employees) = 60% = $600M
- Channel: Cloud-based = 70% = $420M (SAM)
- Market Share: 5-year goal 5% = $21M (SOM)
Data Sources
- Global: Gartner, IDC, Forrester, Statista, Grand View Research
- Korea: Korean IT Industry Association (KAIT), KISA, Statistics Korea
- Free Alternative: Public company IR, industry association reports, CB Insights
Cautions
- Avoid Over-estimation: Conservative filter at each step
- Use Current Data: 2-3 year old reports, adjust for growth
- Confirm Definitions: "CRM" scope varies by report
2. Bottom-up (Bottom to Top)
Process
Unit economics
(Revenue per customer)
↓ × Target customer count
Potential revenue
↓ × Realistic reach rate
SAM
↓ × Conversion rate
SOM
Calculation Example (Accounting SaaS for SMB)
Step 1: Target Customer Count
- Korea SMB (10-100 employees): 150,000 (Statistics Korea)
- Current accounting software users: 80% = 120,000
- Cloud conversion intent: 50% = 60,000 (TAM customers)
Step 2: Customer Revenue
- ARPA (Average Revenue Per Account): ₩300K/month
- Annual: ₩3.6M per customer
Step 3: TAM Calculation
- 60,000 × ₩3.6M = ₩216B (~$180M)
Step 4: SAM (Reachable)
- Sales team can cover: 30% = 18,000 customers
- SAM = 18,000 × ₩3.6M = ₩64.8B ($54M)
Step 5: SOM (5-year target)
- Target share: 5% = 900 customers
- SOM = 900 × ₩3.6M = ₩3.24B ($2.7M ARR)
Data Sources
- Customer Count: Statistics Korea, SME Office, industry associations
- ARPA: Competitor disclosures, beta customer data, pricing pages
- Conversion: Own funnel data, benchmarks (Seed: 1-3%, Series A: 5-10%)
Advantages
- Verifiable: Each step backed by data
- Connects to Execution: SOM reverse-calculates needed customers
- Investor Trust: Specific, credible narrative
3. Value Theory (Value-Based)
Process
Current solution cost
↓ - Our product cost
Savings (or added value)
↓ × Total customer count
TAM
↓ × Adoption target %
SOM
Calculation Example (AI Recruiting Platform)
Step 1: Current Cost
- Avg SMB recruiting cost: ₩5M per hire (20% agency fee)
- Avg hires/year: 5
- Annual recruiting cost: ₩25M/business
Step 2: Our Value
- Reduce agency fee 80%: -₩4M
- Save HR time 50%: -₩1.2M
- Reduce bad hires 30%: -₩1.5M
- Total savings: ₩7.5M/year
Our subscription: ₩1.2M/year
- Net savings: ₩6.3M/year
- ROI: 525%
Step 3: Willingness to Pay
- Customers pay 10-30% of savings: 30% = ₩1.9M
- Our price ₩1.2M is 63% of willingness → attractive
Step 4: TAM
- Target: 50,000 SMBs
- TAM = 50,000 × ₩1.2M = ₩600B (~$50M)
Step 5: SOM
- 5-year adoption: 10% (existing solution replacement)
- SOM = 5,000 customers × ₩1.2M = ₩300B ($25M ARR)
When to Use
- New Categories: No existing market data
- 10x Innovation: Revolutionary product
- B2B ROI: Clear cost savings narrative
Cautions
- Validate Assumptions: "80% savings" proven with beta customer data
- Consider Alternatives: Free/low-cost competing options
- Behavior Change: Value exists, but conversion may be slow
Cross-Validation (Triangulation)
Why It's Needed
- Top-down: Tends to over-estimate
- Bottom-up: Tends to under-estimate (conservative)
- Value Theory: Subjective, hard to prove
→ 3 results in similar range = high confidence
Validation Process
Run 3 Methodologies Independently
- Don't let one result influence another
Compare Results
| Methodology | TAM | SAM | SOM (5-year) |
|--------|-----|-----|-----------|
| Top-down | $200M | $50M | $5M |
| Bottom-up | $180M | $45M | $3M |
| Value Theory | $250M | $60M | $6M |
| **Average** | **$210M** | **$52M** | **$4.7M** |
| **Range** | ±15% | ±14% | ±29% |
Assess Consistency
- ±20% or less: Confident → use average
- ±20-50%: Medium confidence → review assumptions
- ±50%+: Low confidence → re-run methodology
Choose Conservative Value
- Investor: Mid-range or lower 25%
- Internal Plan: Upper range as stretch goal
Example: Analysis Difference
Bottom-up ($45M SAM) vs Top-down ($50M SAM) – Why?:
- Top-down: "SMB" in report includes up to 500 employees
- Bottom-up: We target only 10-100 employees
- Conclusion: Bottom-up is more accurate; adjust Top-down assumptions
Investor Presentation
Slide Structure (1 Page)
# Market Opportunity
## TAM / SAM / SOM
┌──────────────────────────────────────────┐
│ TAM $200M Korea SMB Accounting SaaS │
│ ↓ │
│ SAM $50M 10-100 employees, cloud │
│ ↓ │
│ SOM $5M 5-year 10% market share │
└──────────────────────────────────────────┘
### Methodology (Cross-Validated)
✓ Top-down: Gartner market report basis
✓ Bottom-up: 60,000 targets × ₩3.6M ARPA
✓ Value Theory: ₩6.3M/year savings basis
### Growth Drivers
• Cloud migration acceleration (15% annual)
• Digital tax invoice mandate (2025)
• SMB automation demand increase
Investor Red Flags vs Green Lights
| Check |
RED FLAG 🔴 |
GREEN LIGHT 🟢 |
| TAM Size |
<$500M |
>$1B |
| SAM Logic |
"Everyone" |
Clear segment definition |
| SOM Basis |
"We'll take 10%" |
Unit economics reverse-calc |
| Growth Rate |
Flat market |
10%+ annual growth |
| Competition |
Saturated |
Fragmented or new |
| Methodology |
1 only |
2-3 cross-validated |
Common Mistakes
❌ Over-estimation
- "Global $500B market, we'll take 1% = $5B"
- → Why 1%? How? Plan not shown
❌ TAM = SAM
- Ignores geography, segment, channel constraints
- → "Only Seoul, 3 districts" coverage missed
❌ Static Market
- Current size only, no growth rate
- → What about market in 5 years?
❌ Single Methodology
- Top-down only → unverified
- → Use minimum 2, ideally 3
✅ Good Example
TAM: $2B (2024) → $4B (2029, 15% CAGR)
SAM: $500M (Korea + SMB + SaaS 40% adoption)
SOM: $25M (5-year 5% market share)
Evidence:
• Top-down: Gartner report
• Bottom-up: 60K accounts × ₩5M ARPA
• Beta customer validation: ₩4.8M actual ARPA (±4%)
By Business Model
SaaS
TAM Calculation Basis:
- Total target customers (companies or people)
- ARPA × customer count
- Existing legacy solution market size
Key Assumptions:
- Cloud migration rate (on-premise → SaaS)
- Adoption rate (manual/Excel → software)
- ARPA (price per tier × mix)
Example:
- TAM = 100K companies × $500/month × 12 = $600M
Marketplace
TAM Calculation Basis:
- Total transaction value (GMV) × Take Rate
- OR: Offline market online conversion
Key Assumptions:
- Online penetration rate (e.g., 20% of used car sales)
- Take rate (10-30%, category-specific)
- Transaction frequency
Example:
- Korea used car sales: ₩45 trillion
- Online conversion: 20% = ₩9 trillion GMV
- Take rate: 3% → TAM = ₩270B
Consumer
TAM Calculation Basis:
- Total target users × ARPU
- OR: Replace offline spending
Key Assumptions:
- Target demographic size
- Smartphone adoption (mobile apps)
- Monetization willingness (subscription, IAP, ads)
Example (Fitness app):
- Korea 20-50 age exercise population: 10M
- App usage intent: 10% = 1M
- ARPU: ₩5,000/month → TAM = ₩600B/year
B2B Enterprise
TAM Calculation Basis:
- Account count (enterprises) × ACV
- OR: IT budget category share
Key Assumptions:
- ICP filters (industry, employee count, revenue)
- ACV (SMB <$50K, Mid $50-250K, Ent >$250K)
- Buying committee existence
Example:
- Korea manufacturing (500+ employees): 2,000
- IT budget ₩1B × 5% (our category) = ₩50M
- TAM = 2,000 × ₩50M = ₩100B
Execution Flow
Collect Input
- Product description
- Target customer (region, segment)
- Pricing model (ARPA or ACV)
- Competitors (if known)
Web Research (10-15 queries)
- "Korea [industry] market size 2024"
- "[category] global market size forecast"
- "Number of [target customers] in [region]"
- "[competitor] revenue ARR"
- "ARPA benchmark [industry]"
Top-down Calculation
- Find global/Korea market size
- Apply filters (geography → segment → channel)
- TAM → SAM → SOM
Bottom-up Calculation
- Define target customer count
- Set ARPA
- Apply reach and conversion rates
Value Theory (optional)
- Current solution cost vs our price
- Savings or value addition
- Willingness to pay validation
Cross-Validate
- Compare 3 results
- If ±20% range: use average
- If wider: recheck assumptions
Create Output
- Investor slide (1 page)
- Assumptions doc (detailed calculation)
- Data sources cited
Connected Tools
| Tool Category |
Placeholder |
Use Case |
Example Tools |
| Knowledge Base |
~~knowledge base |
Validate ARPA with internal customer data |
Notion, Confluence |
| Spreadsheet |
~~spreadsheet |
Model market scenarios |
Google Sheets, Excel |
| Data Enrichment |
~~data enrichment |
Verify against competitor data |
THE VC, Innovation Forest, OpenDART |
| CRM |
~~CRM |
Extract actual conversion data |
Relate, HubSpot |
Related Skills
- startup-metrics: Set metrics to achieve SOM
- financial-modeling: Embed market sizing into revenue forecast
- competitive-landscape: Analyze competition within market
- gtm-strategy: Select GTM motion for SAM reach
Tips
- Conservative Assumptions: Investors always suspect over-optimism; downside estimates build credibility
- Growth Markets Preferred: Stagnant market < 10%+ growth
- Do All 3 Methods: 1 method = "not validated" impression; minimum 2, ideally 3
- Cite Data Sources: "Gartner 2024", "Statistics Korea 2023" — specifics matter
- Document Definitions: "SMB = 10-100 employees" — be explicit
- Reverse-Check SOM: $5M SOM ÷ $50K ACV = 100 customers needed. Realistic? Check.
- Market vs Us: TAM is market; SOM is us. Don't confuse.
- Korea Adjustments: Korea market smaller, lower ACV, slower adoption than US → calibrate
Detailed Methodology: See references/methodology-guide.md
1---2name: market-sizing3description: Calculates TAM, SAM, and SOM using three methodologies (top-down, bottom-up, value theory) and cross-validates results for investor-ready market analysis.4---56# Market Sizing78> For unfamiliar placeholders or connected tools, see [CONNECTORS.md](../../CONNECTORS.md).910TAM (Total Addressable Market), SAM (Serviceable Available Market), SOM (Serviceable Obtainable Market) analysis framework. Cross-validates using 3 methodologies (Top-down, Bottom-up, Value Theory) to present compelling market opportunity to investors.1112## How It Works1314```15┌─────────────────────────────────────────────────────────────────┐16│ MARKET SIZING FRAMEWORK │17├─────────────────────────────────────────────────────────────────┤18│ Core Features (Standalone) │19│ ✓ Calculate TAM/SAM/SOM using 3 methodologies │20│ ✓ Web search for industry reports and market data │21│ ✓ Cross-validate with triangulation for confidence │22│ ✓ Create investor-ready visual summary & assumptions doc │23├─────────────────────────────────────────────────────────────────┤24│ Enhanced Mode (with tool connections) │25│ + ~~knowledge base: Refine Bottom-up with internal customer │26│ data │27│ + ~~spreadsheet: Model market size scenarios │28│ + ~~data enrichment: Validate against competitor data │29└─────────────────────────────────────────────────────────────────┘30```3132## Getting Started33341. **Basic Analysis**: "Analyze TAM/SAM/SOM for Korea B2B SaaS CRM"352. **Specific Segment**: "What's the market size for SMB accounting SaaS?"363. **Investor Pitch**: "Create a market sizing slide for Series A pitch"374. **Validate**: "Verify our $5B TAM estimate"3839## TAM / SAM / SOM Definition4041### 3-Tier Framework4243```44┌──────────────────────────────────────────────────────┐45│ TAM (Total) │46│ "Everyone with this problem" │47│ Example: Global CRM market $50B │48│ ┌───────────────────────────────────────────┐ │49│ │ SAM (Serviceable) │ │50│ │ "People we can reach" │ │51│ │ Example: Korea SMB CRM $500M │ │52│ │ ┌─────────────────────────────────┐ │ │53│ │ │ SOM (Obtainable) │ │ │54│ │ │ "Realistic capture target" │ │ │55│ │ │ Example: 3-year goal $15M (3%) │ │ │56│ │ └─────────────────────────────────┘ │ │57│ └───────────────────────────────────────────┘ │58└──────────────────────────────────────────────────────┘59```6061### Each Tier Defined6263| Tier | Definition | Key Question | Investor Focus |64|------|-----------|--------------|-----------------|65| **TAM** | Total addressable market | "If all potential customers used us?" | Is market big enough? ($1B+ preferred) |66| **SAM** | Serviceable available market | "Who can our business model reach?" | Is target realistic? |67| **SOM** | Serviceable obtainable market | "How much can we realistically capture?" | Is execution feasible? |6869### Typical Ratios70- **SAM**: 10-50% of TAM (geography, segment, channel constraints)71- **SOM**: 2-10% of SAM (3-5 year goal, competition considered)7273**Example** (Global SaaS CRM):74- TAM: $50B (all enterprises worldwide)75- SAM: $5B (Korea + SMB + cloud-based)76- SOM: $150M (5-year 3% market share goal)7778---7980## 3 Methodologies8182### Methodology Comparison8384| Methodology | Approach | Advantages | Disadvantages | Best For |85|------------|----------|-----------|----------------|----------|86| **Top-down** | Market → Segment | Fast, uses reports | Many assumptions, over-estimates | Mature market, initial estimates |87| **Bottom-up** | Unit economics → Aggregate | Accurate, realistic | Data-heavy, time-consuming | Validated Unit Economics |88| **Value Theory** | Customer value creation | Fits new markets, differentiates | Subjective, hard to prove | New categories, 10x products |8990**Recommendation**: Execute all 3, then cross-validate (Triangulation)9192### 1. Top-down (Top to Bottom)9394#### Process9596```97Entire market size98 ↓ Region filter (example: Korea = 2% of global)99Korea market size100 ↓ Segment filter (example: SMB = 60%)101Target segment102 ↓ Adoption rate (example: cloud conversion = 40%)103SAM104 ↓ Market share target (example: 5% in 5 years)105SOM106```107108#### Calculation Example (CRM SaaS)1091101. **TAM**: Global CRM market = $50B (Gartner 2024)1112. **Region Filter**: Korea = 2% of global = $1B1123. **Segment**: SMB (10-500 employees) = 60% = $600M1134. **Channel**: Cloud-based = 70% = **$420M (SAM)**1145. **Market Share**: 5-year goal 5% = **$21M (SOM)**115116#### Data Sources117- **Global**: Gartner, IDC, Forrester, Statista, Grand View Research118- **Korea**: Korean IT Industry Association (KAIT), KISA, Statistics Korea119- **Free Alternative**: Public company IR, industry association reports, CB Insights120121#### Cautions122- **Avoid Over-estimation**: Conservative filter at each step123- **Use Current Data**: 2-3 year old reports, adjust for growth124- **Confirm Definitions**: "CRM" scope varies by report125126### 2. Bottom-up (Bottom to Top)127128#### Process129130```131Unit economics132 (Revenue per customer)133 ↓ × Target customer count134Potential revenue135 ↓ × Realistic reach rate136SAM137 ↓ × Conversion rate138SOM139```140141#### Calculation Example (Accounting SaaS for SMB)142143**Step 1: Target Customer Count**144- Korea SMB (10-100 employees): 150,000 (Statistics Korea)145- Current accounting software users: 80% = 120,000146- Cloud conversion intent: 50% = **60,000 (TAM customers)**147148**Step 2: Customer Revenue**149- ARPA (Average Revenue Per Account): ₩300K/month150- Annual: ₩3.6M per customer151152**Step 3: TAM Calculation**153- 60,000 × ₩3.6M = **₩216B (~$180M)**154155**Step 4: SAM (Reachable)**156- Sales team can cover: 30% = 18,000 customers157- SAM = 18,000 × ₩3.6M = **₩64.8B ($54M)**158159**Step 5: SOM (5-year target)**160- Target share: 5% = 900 customers161- SOM = 900 × ₩3.6M = **₩3.24B ($2.7M ARR)**162163#### Data Sources164- **Customer Count**: Statistics Korea, SME Office, industry associations165- **ARPA**: Competitor disclosures, beta customer data, pricing pages166- **Conversion**: Own funnel data, benchmarks (Seed: 1-3%, Series A: 5-10%)167168#### Advantages169- **Verifiable**: Each step backed by data170- **Connects to Execution**: SOM reverse-calculates needed customers171- **Investor Trust**: Specific, credible narrative172173### 3. Value Theory (Value-Based)174175#### Process176177```178Current solution cost179 ↓ - Our product cost180Savings (or added value)181 ↓ × Total customer count182TAM183 ↓ × Adoption target %184SOM185```186187#### Calculation Example (AI Recruiting Platform)188189**Step 1: Current Cost**190- Avg SMB recruiting cost: ₩5M per hire (20% agency fee)191- Avg hires/year: 5192- Annual recruiting cost: ₩25M/business193194**Step 2: Our Value**195- Reduce agency fee 80%: -₩4M196- Save HR time 50%: -₩1.2M197- Reduce bad hires 30%: -₩1.5M198- Total savings: ₩7.5M/year199200**Our subscription**: ₩1.2M/year201- **Net savings**: ₩6.3M/year202- **ROI**: 525%203204**Step 3: Willingness to Pay**205- Customers pay 10-30% of savings: 30% = ₩1.9M206- Our price ₩1.2M is 63% of willingness → attractive207208**Step 4: TAM**209- Target: 50,000 SMBs210- TAM = 50,000 × ₩1.2M = **₩600B (~$50M)**211212**Step 5: SOM**213- 5-year adoption: 10% (existing solution replacement)214- SOM = 5,000 customers × ₩1.2M = **₩300B ($25M ARR)**215216#### When to Use217- **New Categories**: No existing market data218- **10x Innovation**: Revolutionary product219- **B2B ROI**: Clear cost savings narrative220221#### Cautions222- **Validate Assumptions**: "80% savings" proven with beta customer data223- **Consider Alternatives**: Free/low-cost competing options224- **Behavior Change**: Value exists, but conversion may be slow225226---227228## Cross-Validation (Triangulation)229230### Why It's Needed231232- **Top-down**: Tends to over-estimate233- **Bottom-up**: Tends to under-estimate (conservative)234- **Value Theory**: Subjective, hard to prove235236→ **3 results in similar range = high confidence**237238### Validation Process2392401. **Run 3 Methodologies Independently**241 - Don't let one result influence another2422432. **Compare Results**244 ```245 | Methodology | TAM | SAM | SOM (5-year) |246 |--------|-----|-----|-----------|247 | Top-down | $200M | $50M | $5M |248 | Bottom-up | $180M | $45M | $3M |249 | Value Theory | $250M | $60M | $6M |250 | **Average** | **$210M** | **$52M** | **$4.7M** |251 | **Range** | ±15% | ±14% | ±29% |252 ```2532543. **Assess Consistency**255 - **±20% or less**: Confident → use average256 - **±20-50%**: Medium confidence → review assumptions257 - **±50%+**: Low confidence → re-run methodology2582594. **Choose Conservative Value**260 - **Investor**: Mid-range or lower 25%261 - **Internal Plan**: Upper range as stretch goal262263### Example: Analysis Difference264265**Bottom-up ($45M SAM) vs Top-down ($50M SAM) – Why?**:266- Top-down: "SMB" in report includes up to 500 employees267- Bottom-up: We target only 10-100 employees268- **Conclusion**: Bottom-up is more accurate; adjust Top-down assumptions269270---271272## Investor Presentation273274### Slide Structure (1 Page)275276```markdown277# Market Opportunity278279## TAM / SAM / SOM280281┌──────────────────────────────────────────┐282│ TAM $200M Korea SMB Accounting SaaS │283│ ↓ │284│ SAM $50M 10-100 employees, cloud │285│ ↓ │286│ SOM $5M 5-year 10% market share │287└──────────────────────────────────────────┘288289### Methodology (Cross-Validated)290✓ Top-down: Gartner market report basis291✓ Bottom-up: 60,000 targets × ₩3.6M ARPA292✓ Value Theory: ₩6.3M/year savings basis293294### Growth Drivers295• Cloud migration acceleration (15% annual)296• Digital tax invoice mandate (2025)297• SMB automation demand increase298```299300### Investor Red Flags vs Green Lights301302| Check | RED FLAG 🔴 | GREEN LIGHT 🟢 |303|-------|------------|-----------------|304| **TAM Size** | <$500M | >$1B |305| **SAM Logic** | "Everyone" | Clear segment definition |306| **SOM Basis** | "We'll take 10%" | Unit economics reverse-calc |307| **Growth Rate** | Flat market | 10%+ annual growth |308| **Competition** | Saturated | Fragmented or new |309| **Methodology** | 1 only | 2-3 cross-validated |310311### Common Mistakes312313❌ **Over-estimation**314- "Global $500B market, we'll take 1% = $5B"315- → Why 1%? How? Plan not shown316317❌ **TAM = SAM**318- Ignores geography, segment, channel constraints319- → "Only Seoul, 3 districts" coverage missed320321❌ **Static Market**322- Current size only, no growth rate323- → What about market in 5 years?324325❌ **Single Methodology**326- Top-down only → unverified327- → Use minimum 2, ideally 3328329✅ **Good Example**330```331TAM: $2B (2024) → $4B (2029, 15% CAGR)332SAM: $500M (Korea + SMB + SaaS 40% adoption)333SOM: $25M (5-year 5% market share)334335Evidence:336• Top-down: Gartner report337• Bottom-up: 60K accounts × ₩5M ARPA338• Beta customer validation: ₩4.8M actual ARPA (±4%)339```340341---342343## By Business Model344345### SaaS346347**TAM Calculation Basis**:348- Total target customers (companies or people)349- ARPA × customer count350- Existing legacy solution market size351352**Key Assumptions**:353- Cloud migration rate (on-premise → SaaS)354- Adoption rate (manual/Excel → software)355- ARPA (price per tier × mix)356357**Example**:358- TAM = 100K companies × $500/month × 12 = $600M359360### Marketplace361362**TAM Calculation Basis**:363- Total transaction value (GMV) × Take Rate364- OR: Offline market online conversion365366**Key Assumptions**:367- Online penetration rate (e.g., 20% of used car sales)368- Take rate (10-30%, category-specific)369- Transaction frequency370371**Example**:372- Korea used car sales: ₩45 trillion373- Online conversion: 20% = ₩9 trillion GMV374- Take rate: 3% → TAM = ₩270B375376### Consumer377378**TAM Calculation Basis**:379- Total target users × ARPU380- OR: Replace offline spending381382**Key Assumptions**:383- Target demographic size384- Smartphone adoption (mobile apps)385- Monetization willingness (subscription, IAP, ads)386387**Example** (Fitness app):388- Korea 20-50 age exercise population: 10M389- App usage intent: 10% = 1M390- ARPU: ₩5,000/month → TAM = ₩600B/year391392### B2B Enterprise393394**TAM Calculation Basis**:395- Account count (enterprises) × ACV396- OR: IT budget category share397398**Key Assumptions**:399- ICP filters (industry, employee count, revenue)400- ACV (SMB <$50K, Mid $50-250K, Ent >$250K)401- Buying committee existence402403**Example**:404- Korea manufacturing (500+ employees): 2,000405- IT budget ₩1B × 5% (our category) = ₩50M406- TAM = 2,000 × ₩50M = ₩100B407408---409410## Execution Flow4114121. **Collect Input**413 - Product description414 - Target customer (region, segment)415 - Pricing model (ARPA or ACV)416 - Competitors (if known)4174182. **Web Research** (10-15 queries)419 - "Korea [industry] market size 2024"420 - "[category] global market size forecast"421 - "Number of [target customers] in [region]"422 - "[competitor] revenue ARR"423 - "ARPA benchmark [industry]"4244253. **Top-down Calculation**426 - Find global/Korea market size427 - Apply filters (geography → segment → channel)428 - TAM → SAM → SOM4294304. **Bottom-up Calculation**431 - Define target customer count432 - Set ARPA433 - Apply reach and conversion rates4344355. **Value Theory** (optional)436 - Current solution cost vs our price437 - Savings or value addition438 - Willingness to pay validation4394406. **Cross-Validate**441 - Compare 3 results442 - If ±20% range: use average443 - If wider: recheck assumptions4444457. **Create Output**446 - Investor slide (1 page)447 - Assumptions doc (detailed calculation)448 - Data sources cited449450---451452## Connected Tools453454| Tool Category | Placeholder | Use Case | Example Tools |455|---------------|-------------|----------|----------------|456| Knowledge Base | `~~knowledge base` | Validate ARPA with internal customer data | Notion, Confluence |457| Spreadsheet | `~~spreadsheet` | Model market scenarios | Google Sheets, Excel |458| Data Enrichment | `~~data enrichment` | Verify against competitor data | THE VC, Innovation Forest, OpenDART |459| CRM | `~~CRM` | Extract actual conversion data | Relate, HubSpot |460461---462463## Related Skills464465- **startup-metrics**: Set metrics to achieve SOM466- **financial-modeling**: Embed market sizing into revenue forecast467- **competitive-landscape**: Analyze competition within market468- **gtm-strategy**: Select GTM motion for SAM reach469470---471472## Tips473474- **Conservative Assumptions**: Investors always suspect over-optimism; downside estimates build credibility475- **Growth Markets Preferred**: Stagnant market < 10%+ growth476- **Do All 3 Methods**: 1 method = "not validated" impression; minimum 2, ideally 3477- **Cite Data Sources**: "Gartner 2024", "Statistics Korea 2023" — specifics matter478- **Document Definitions**: "SMB = 10-100 employees" — be explicit479- **Reverse-Check SOM**: $5M SOM ÷ $50K ACV = 100 customers needed. Realistic? Check.480- **Market vs Us**: TAM is market; SOM is us. Don't confuse.481- **Korea Adjustments**: Korea market smaller, lower ACV, slower adoption than US → calibrate482483**Detailed Methodology**: See [references/methodology-guide.md](references/methodology-guide.md)