TAM, SAM, SOM for African startups.

• TAM — Total Addressable Market
  The total annual revenue if every economic actor who could ever buy your product did so at your price. For African startups: top-down by sector (e.g. African fintech revenue pool, African logistics spend), cross-checked against World Bank, IMF, GSMA, or central bank data. Cite sources.
• SAM — Serviceable Addressable Market
  The slice of TAM reachable by your channel, language, regulation, and infrastructure today. A pan-African TAM rarely converts into a pan-African SAM in year one — regulation, FX, and last-mile rails fragment it sharply.
• SOM — Serviceable Obtainable Market
  The realistic share you can capture in 3–5 years given your distribution, capital, and team. This is the number that should drive your operating plan and your raise.

"1.4 billion Africans × $X" produces a number, not a market. Income distribution is heavily skewed, banked and connected populations are smaller than headline figures suggest, and purchasing power varies by 10× across cities, let alone countries. A credible TAM starts from spend pools — what is already being paid for the problem today — not from demographic potential.

Use bottom-up validation: take a single city or corridor you understand, size it precisely, then extrapolate to comparable corridors with explicit adjustments for income, infrastructure, and regulation. Investors trust extrapolation from one verified unit far more than a continent-wide multiplication.

Suppose you're building an SME payments product. A common mistake is "Africa has 44m SMEs × $400 ARPU = $17.6B TAM". A grounded build looks more like:

• TAM
  Formal + semi-formal SMEs in your target geographies (Nigeria, Kenya, Egypt, South Africa, Ghana) × realistic annual payments-tooling spend, benchmarked against existing processor revenue disclosures.
• SAM
  SMEs in your two launch geographies that fit your channel (digitally onboarded, transacting above a minimum volume, within the regulatory perimeter you operate in).
• SOM
  What your sales motion can actually onboard in 36 months — tied to rep capacity, partner integrations live, and compliance throughput. Usually 1–5% of SAM, not 20%.

SOM is not a forecast — it is a function of the operating engine you put behind the product. A founder pitching SOM should be able to show the GTM motion that produces it: channel mix, partner pipeline, sales capacity, conversion assumptions, and the rate at which those scale.

This is the gap the GTM venture operating company model exists to close. Capital can underwrite TAM. Only operators can underwrite SOM. In African markets, where capital has matured faster than the operator stack, the SOM line is where most theses break — and where embedded execution changes the trajectory.

• Cite every source
  World Bank, IMF, GSMA, central banks, regulator filings, listed-comparable disclosures. Vague secondary sources cost credibility.
• Show the bottom-up build
  One verified city or corridor, then explicit extrapolation. Top-down alone reads as marketing.
• Tie SOM to the operating plan
  SOM should reconcile to headcount, channel partners, and regulatory milestones in your 36-month plan.
• Acknowledge fragmentation
  FX, regulation, language, and last-mile rails fragment African TAM. Naming this signals operator maturity.