Research, then more research, then a lot more research.
To find a profitable product you need to know the potential competition, what they are currently selling, and what they are selling the product for.
You need to know what areas have problems with no current solutions.
You need to know what products people are looking for and what they are willing to pay.
You need to be an expert so you can identify products that are currently being sold that may be marketed incorrectly. These are the kinds of products you can create an effective advertising campaign to reach the right customers in the right markets.
Take a walk thru your local mass merchant. What do you see? If you just see a big mess of assorted products, you need to look more closely. In a big brick and mortar store, every product in the store is placed there for a reason. Each store is organized by departments, and each department has an employee or staff at the corporate level that is in charge of each department. These are called buyers, category managers, product managers, merchandisers, or some other descriptive term. These are the “experts” that have done their research and determined what should be in the product mix or what should be offered for sale.
You need to develop your research so you become the expert with regards to your chosen product. Research and product knowledge are your strategies.