<aside> 💡
The segmentation decisions in the previous section are only as strong as the evidence and reasoning behind them. This page is where that evidence lives. A lot of founders make segmentation decisions quickly, intuitively and without documentation. That works until a co-founder disagrees, an investor asks how you arrived at your targeting decisions, or your first 90 days of sales data suggests you may have picked the wrong segment. Document your sources, your decisions and your assumptions here. Revisiting an undocumented segmentation model six months later is nearly impossible.
</aside>
The credibility of your segmentation model depends entirely on the quality of the evidence behind it. A segment that looks attractive based on one industry report and a gut feel is a very different proposition from one validated by market data, customer interviews, and competitive analysis combined.
Log all of the sources that informed your segmentation decisions below. The strongest segmentation models draw on both quantitative sources - market reports, industry databases, LinkedIn data - and qualitative sources - customer interviews, founder conversations, sales call transcripts. If your source list is entirely one type, that is a gap worth closing before you commit significant resources to a targeting decision.
Quantitative Sources
| Source | Type | Key Data Point or Insight | Confidence | Relevance to Segmentation Decision |
|---|---|---|---|---|
| [e.g. Gartner Market Guide 2024] | Industry report | High / Medium / Low | ||
| [Source 2] | ||||
| [Source 3] | ||||
| [Source 4] |
Qualitative Sources
| Source | Type | Key Insight | Confidence | Relevance to Segmentation Decision |
|---|---|---|---|---|
| [e.g. Discovery call with [role] at [company]] | Customer interview | High / Medium / Low | ||
| [Source 2] | ||||
| [Source 3] | ||||
| [Source 4] |
<aside> 💡
Include both quantitative sources (market reports, LinkedIn data, industry databases) and qualitative sources (customer interviews, founder conversations, sales calls, reddit discussions). The strongest segmentation decisions are grounded in both. If you have fewer than three qualitative sources, treat that as a signal - not a blocker. It means customer discovery is still ahead of you, not behind you.
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<aside> 💡
Document every significant segmentation decision here - the ones that shaped your targeting model and that you would need to explain to a new co-founder, a board member, or a sales hire joining in six months. A decision without a rationale is just a preference. A decision with a rationale and documented assumptions is something you can actually stress-test, defend, and update as you learn. Mark each decision with a status. Your segmentation model should be a living document - not a snapshot frozen at the moment you first built it.
</aside>
| Decision | Rationale | Key Assumptions | Date | Status |
|---|---|---|---|---|
| [e.g. Targeting seed to Series A founders before enterprise] | [Why] | [What would need to be true] | [Date] | Confirmed / Under Review / Invalidated |
| [e.g. Focusing on Australia before the US] | [Why] | [What would need to be true] | [Date] | Confirmed / Under Review / Invalidated |
| [e.g. Deprioritising SMB despite its size] | [Why] | [What would need to be true] | [Date] | Confirmed / Under Review / Invalidated |
| [e.g. Choosing B2B over B2C despite early B2C interest] | [Why] | [What would need to be true] | [Date] | Confirmed / Under Review / Invalidated |
| [Decision 5] |
Review and update the status column every quarter. A decision marked Confirmed at pre-launch may look very different at month six when you have real sales data.