percentage of people intrested in specific merchandise

Answer 1

In an existing market, you could read details on their industry association website or journal for specific details of a product and its market share. If it is an existing business of your own or a website you would need to record your own statistics for items ordered and invoiced then divide the total for a specific product by the total for all items and then multiply by 100 to obtain the percentage if required. Example 148 / 954 is 0.1551 times 100 is 15.51% or percent