Market Sizer Data

market-sizer-data

Agent: Analytics Lead

L1 analytics leader (1x) responsible for search demand validation, market sizing, goal framing, instrumentation strategy, and north star metric governance.

Department ethos: ideal-data-growth.md

Skill Description

The market sizer quantifies the total addressable market (TAM), serviceable addressable market (SAM), and serviceable obtainable market (SOM) using bottom-up data models, search demand signals, and public data sources to validate whether a product opportunity justifies investment.

When to Use

• When a new product concept needs market size validation before entering the build phase.
• When investors or leadership request a data-backed market sizing for a pitch or business case.
• When the growth team needs segment-level sizing to prioritize acquisition channels.
• When a pivot or expansion into an adjacent market requires re-sizing the opportunity.

Workflow

1. Define the market boundary: Specify the product category, geography, customer segment, and time horizon. Document inclusion and exclusion criteria.
2. Gather data sources: Collect search volume data, industry reports, census data, competitor revenue proxies, and any internal usage data. Note the recency and reliability of each source.
3. Build bottom-up model: Estimate the number of potential customers in the segment, the expected adoption rate, and the average revenue per user (ARPU). Multiply to produce SAM and SOM.
4. Build top-down cross-check: Use industry revenue data or analyst reports to estimate TAM. Compare top-down and bottom-up figures; investigate divergences greater than 2x.
5. Sensitivity analysis: Vary key assumptions (adoption rate, ARPU, segment size) across low/mid/high scenarios. Present the range rather than a single point estimate.
6. Document and present: Produce a market sizing brief with methodology, data sources, assumptions, scenario outputs, and confidence level.

Anti-Patterns

• Single-source sizing: Relying on one analyst report or one data source produces fragile estimates. Why: any single source may have sampling bias, outdated figures, or different market definitions.
• TAM as the pitch number: Presenting TAM instead of SOM inflates the opportunity and misleads stakeholders. Why: TAM includes segments the product cannot realistically reach; SOM is the actionable figure.
• Point estimates without ranges: Delivering a single market size number hides the uncertainty inherent in every assumption. Why: decision-makers need to understand the downside scenario, not just the midpoint.
• Ignoring willingness to pay: Sizing by headcount without validating price sensitivity overstates revenue potential. Why: a large addressable population at zero willingness to pay is not a market.

Output

Success:

• A market sizing brief containing TAM, SAM, and SOM with methodology, data sources, assumption log, sensitivity analysis across three scenarios, and a confidence rating.

Failure:

• Market sizing relies on a single source or uses TAM as the primary figure. Report the data gap, recommend additional sources, and flag which assumptions need validation.

Related Skills

• search-demand-validator -- search demand data is a key input to bottom-up market sizing.
• market-sizer -- the product manager's market sizer focuses on opportunity framing; this skill provides the quantitative backing.