market-sizing

Produce a market sizing estimate for $ARGUMENTS with explicit methodology.

Step 1: Define the market

A market size without a definition is a number without meaning. Establish:

• Buyer: who is paying? (individual, SMB, enterprise, government department)
• Purchase unit: what are they buying? (subscription, one-time, services engagement)
• Geography: global, country-level, or regional?
• Time horizon: current year, or a projected year?

State these assumptions explicitly. Different assumptions produce wildly different numbers — the definition IS the methodology.

Step 2: Top-down estimate

Find analyst estimates from credible sources:

• Gartner — technology markets
• IDC — technology markets
• Grand View Research — broad industry coverage
• IBISWorld — AU industry reports specifically (ibisworld.com/au)
• ABS — AU macro/industry data
• Stats NZ — NZ industry data

For each estimate: note the specific report title, year published, and the exact figure cited. Never round-trip a sourced figure without the original citation.

If no analyst report exists for this specific market, note it and proceed to bottom-up.

Step 3: Bottom-up estimate

Build independently from first principles:

1. Estimate addressable customer count — how many potential buyers exist? (Use industry association data, government statistics, LinkedIn company size filters as proxies)
2. Estimate average annual spend — what does a typical buyer spend? (Use public pricing, customer testimonials, analyst benchmarks)
3. Apply realistic penetration — what share could be captured at maturity? (Comparable market penetration rates from analogous markets)

Show the calculation explicitly: N customers × $X avg spend × Y% penetration = $Z

Step 4: Reconcile

Do the top-down and bottom-up figures agree within 2x?

• Yes: report both, note the alignment as confidence signal
• No: explain the variance. Common reasons: different market definitions, different geographies, different buyer segmentation. Don't average them — resolve the discrepancy

Step 5: Growth rate

Find CAGR from:

• Analyst report projections (preferred)
• Public company revenue growth rates in the space (proxy — available from earnings reports)
• VC/PE investment velocity as a leading signal

Note the source and the period it covers.

Rules

• A market size without methodology is a guess wearing a number's clothes. Always show the working.
• Label all estimates as estimates. Never present a number as fact unless it comes from a primary regulatory or government source.
• Top-down and bottom-up must both be attempted. If one genuinely can't be done, explain why.
• Don't average unreconciled top-down and bottom-up figures. Diagnose the gap instead.
• Distinguish TAM (total addressable), SAM (serviceable addressable), and SOM (serviceable obtainable) if the question calls for it. If not asked, default to TAM and state what's included.

Output format

## Market sizing: [Market name]

**As of:** [date]
**Market definition:** [buyer, purchase unit, geography, time horizon]

### Size estimates

| Method | Estimate | Source | Methodology |
|---|---|---|---|
| Top-down | $Xbn | [Analyst report, year] | [Brief description] |
| Bottom-up | $Xbn | Own calculation | [N customers × $X spend × Y% penetration] |

### Reconciliation

[Do the figures align? If not, why not?]

### Growth rate

[CAGR estimate with source and period]

### Confidence: [High / Medium / Low]

[Reasoning — do multiple sources agree? How recent is the data? How well-defined is the market?]

### Sources

1. [Title](URL) — [what it contributed]