The principles of determining market share and market potential are the same no matter how large the geographical area. You must first determine a customer profile, the size of the market, and the number of competitors. You could also use a readership survey given to you by a magazine in which you intend to advertise. By definition we know that markup as a percentage is given as a percentage of sales. Pricing is based normally on a combination of cost and market competition.
Trade associations are a prime source of such information.
Average net profits vary with the type of business - retail, wholesale, service, manufacturing, construction. They also vary for the type of business structure - proprietorship or corporation. ROI is net profit divided by capital invested by the owners of the company. ROI is used to measure the effectiveness of management in attaining the owners' desired return on their investment. Generally, the larger the ROI, the more attractive a company is to potential investors.