Something I noticed while practicing market sizing was that most cases only seem to consider the private/household side of the market, and there is very little guidance on how to estimate the commercial side.
This leaves 2 options:
1. Ignore this segment which will cause interviewers to wonder if this was missed
2. Propose this and pray the interviewer says we can ignore it
When asked to size the commercial side, I usually opt for one of the two approaches:
1. % of household market
2. # of commercial buildings as a driver (but this is not robust since some commercial buildings are multi-storied offices and it is hard to narrow down what % of the buildings are for relevant industries).
Is there a more robust way of estimating the commercial side? Say, when estimating the size of the bucket/pail market in Thailand, how can we estimate the buckets purchased by businesses?