Businesses usually need to use both primary and secondary data collection, but for different purposes.
When you are developing a new product line, you should begin with secondary research data. This will likely be both government demographic data and data from other research you have conducted for other lines. Once you have established a target market and its needs, you can conduct research to collect primary data to develop your new product line.
After all the secondary data sources have been checked and the needed data have not been found, the third aspect of a research projected begins the collection of data through primary research. (enotes, see first link)
Let’s say you are developing a new kind of lipstick. The first question: What is your demographic? Since the population is growing most in the Baby Boomers, you might want to consider developing a lipstick for older women. However, you need to access government democratic data first in order to determine if there really is a large market of aging women you can reach.