What percent of market will visit my store

You've hit the core value of making good estimates in business. Always try to go from information you know, or information you can find out, to some logical extension that makes sense.

In this case, find out the percentage of people who visit other venues that might attract a similar percentage. There are several ways to go for that information. You're best bet is to use all of them:

1. Find some data from some authoritative source. Look for an industry association, published statistics, magazine, or something similar. Depends on what your store is, of course, but there may be published data.
2. Find a similar store -- or better yet several -- in other similar locations, and ask them. Use the telephone. If you're in one destination city and they're in another, you don't compete, and you can ask them.
3. Find similar stores in your area that don't sell the same thing you do, but attract the same kind of customers. Ask them.
4. Find the stores you'll compete against, park your car near them, and count their customers. Take a day or two, or even an hour or two, and count how many people go in. Try to take 3-4 random sampling hours.

Thank you for your question.

Tim Berry