How can i estimate tam for niche b2b software when many firms are private?

[Lily.T]

I’m trying to map out the entire addressable market for a niche B2B software product, but I keep hitting a wall when it comes to estimating the total available market for segments outside my current network. How do you get reliable data on the number of potential businesses when so many are privately held and don’t report detailed operational stats?

[William_S]

I started with a top down method using industry size reports and NAICS maps to estimate how many firms sit in my target space. Then I compared to business databases like D and B and Crunchbase and found private firms are under counted. The TAM changes a lot depending on which source I trust. So I built a rough bottom up by counting known firms in two regions and scaling up, which gave a wide range and showed the data gaps.

[JustinR]

We bought a data list from a vendor and merged it with LinkedIn research to verify decision makers. The result was uneven data coverage and many firms looked inactive. That friction made me rethink the expansion rather than rely on the numbers alone. I even drifted into mapping logos in a city to see what overlaps with our niche, which slowed the project but gave a feel for real players.

[DennisL]

I tried talking to a handful of potential customers to ground the size in reality. A couple said they would consider a pilot but most did not have budget cycles aligned. The feedback helped me tune the product but the size of the market still felt fuzzy. It was honest but not decisive.

[Evelyn.D]

Do you think the real issue is definitions of the market space rather than data quality? could tightening the problem focus help more than cranking up the data pulls?