Secondary research data collection is used when a business outsources the collection of data by hiring external firms or consultants to collect and possibly analyze the data.
Secondary data collection may be an economical way for a business to gather data for product development or marketing, it allows a company to explore new areas where it does not already have experience, and determine if an area is appropriate for expansion without expending too many resources.
Secondary data is generally less costly and less time consuming than gathering primary data, typically is accumulated before primary data is gathered, and may even help determine the course by which primary data is pursued. (enotes, see first link)
However, there are also disadvantage of secondary research collection. When you are not the one collecting the data, you do not have complete control of the process. If the data was collected for some other purpose (even by someone within your organization), it may not be exactly what you need. The data might also be interpreted differently than someone within your firm would have interpreted it.
In today's world of rapidly growing information technologies, secondary data are available from numerous sources. A researcher should explore the existing data before starting the research process. (enotes, see first link)
An example of secondary data collection is marketing research firms or government agencies that collect population data. Since your company did not collect the data, it does not have the ability to refine the collection process to meet its specific needs. A study conducted for that specific purpose would likely yield more accurate data.
In summary, there are both advantages and disadvantages of secondary research data. It is often a less costly way to go. You should always look closely at the data to make sure it meets you needs.