Market Demand
Research the products or services you have developing for their market demand.

Find customers that are likely to buy your products or services.

Your products or services should have a name or logo which identifies you from all others.

Target the buying market needs considered valuable within your products or services you are selling.

Know what your customers think of your products or services.

Competitors
Research what your competition is doing to market and sell products or services that you are seeking to sell or currently selling. Investigate your competitors:

What are their successful sales actions?
What are their secrets to getting new customers?
Who are the leaders in the industry?
How do they sell their products? What is their pricing?
What is their positioning in the market?
How would you best sell against them?
What do their customers think of them?
What motivates customers to buy the competition's products or services instead of yours?