The phrase "primary research" simply refers to those sources of information who have first-hand knowledge of the event being discussed, or that reflect one's own collection of data, whether through surveys or other types of research. Within the realm of business, which is specified by the questioner, primary research would involve surveying consumers, distributors (if appropriate), suppliers (if appropriate) or any other component of the business operation, for the purpose of ascertaining what aspects of those operations require improvement.
In an academic context, "primary" research involves going out and interviewing individuals who are actively, or were in the past, involved in the event or chain of events being studied. For example, if a student or researcher is studying policy-making in the government, he or she would want to interview individuals working in the government agency that is the focus of the research, including both high-level and mid-level officials.
In the physical sciences, "primary" research involves actually performing experiements oneself, rather than relying on someone else's findings.
Primary research is distinguished from secondary research by its emphasis on personal observation, rather than what one reads about in books or articles.