I'm in sales. This is going to sound shallow and tautological, but you find the people to interview for Product Market Fit by looking for the people you THINK are the ideal customers.
If you can't find your target market, you might want to consider a different demographic that you understand better. Most successful startup founders started a business specifically to solve the problems they dealt with at their last job. They understand their product market fit because they ARE their target market.
If you can't find your target market, you might want to consider a different demographic that you understand better. Most successful startup founders started a business specifically to solve the problems they dealt with at their last job. They understand their product market fit because they ARE their target market.