Many companies I've done strategic planning with have gotten really worked up over trying to estimate the size of a niche market when there is little or no available data on the market.
I figure there are four easy Ways to figure out the size of your market segment.
1. Total up the sales of your competitors in the segment
2. Total up the purchases of the customers in the segment
3. Take your sales in the segment, estimate your share, and multiply
4. Total up the sales of key suppliers into the segment and estimate the sales number this represents
Naturally, each of these requires that you have some information, or at least guesses about what is going on in your markets. If you'd like me to explore how to do each of these, let me know and I will write more on the topic.
Do you have another way to estimate market size? I'd be interested in hearing from you if you do.
Also, if you know anyone who is looking for a strategic planning speaker - I love to speak at conventions and corporate events...drop me a line!