How do I turn broad TAM into a true SAM for a niche B2B software product?

[Zachary_W]

I’m trying to map out the total addressable market for a niche B2B software product, but I’m stuck on how to accurately estimate the number of potential buyers. My initial sizing feels too broad, and I’m worried I’m including firms that would never realistically purchase. How have others narrowed down from a broad industry classification to a true serviceable market?

[Riley.R]

I did this last year. Started with an ICP built from pain points, not just industry codes. Narrowed to mid‑market manufacturers with 50–300 employees, budget authority for software, and a use case around workflow automation. I sanity‑checked with about a dozen discovery calls and trimmed the list from thousands to a few hundred who could actually buy.

[GraceXM]

I once overfiltered and still ended up with no budget conversation. Filtering by industry and country without confirming a live project or budget line left me talking to people who weren’t in a buying cycle. We added a pre‑qualification step: does this account have a current project or budget for something like this in the next 6–12 months? That saved time, but the quality was slow to come in.

[Jonathan.G]

Is the real problem the procurement cycle rather than the TAM? It felt that way sometimes. Even with a tight ICP, committees, risk reviews, and vendor vetting drag things out. I started tracking time‑to‑approval and the number of stakeholders involved instead of just counts of potential buyers.

[LukeT]

I try to keep it grounded with a tiny pilot. A map of clusters, then a 2‑month pilot with 3 accounts to see if the pain translates to adoption and expansion. We measured activation and occasional upsell signals, and the numbers moved as we learned who actually used it and who became champions.