In business, primary data is preferred when the data is crucial to new product development or a new marketing plan. Secondary data is acceptable and even preferred in the beginning stages of a project, where exploration is the goal.
Data can be primary or secondary, and whether one or both are used, and which is used, depends largely on the research question and the availability of these data sources. (enotes, see source 1)
Consider that your business is considering designing a new product for a new market. In the early stages of the product development and market research, you will want to cast a wide net for data.
You can use secondary data collected by your own company from prior research, or by other agencies such as government census data. This data will allow you to focus your study on a particular area so that when you do collect primary data you can do so productively.
Once you have used your secondary data to become acquainted with the demographic or product, you can focus your efforts on a specific set of data. Because you have done your homework, you will not be wasting your time and efforts.