DATA SOURCES The researcher can gather secondary data, primary data, or both. Secondary
data are data that were collected for another purpose and already exist somewhere. Primary data
are data freshly gathered for a specific purpose or for a specific research project.
Researchers usually start their investigation by examining some of the rich variety of low-cost
and readily available secondary data, to see whether they can partly or wholly solve the problem
without collecting costly primary data. For instance, auto advertisers looking to get a better return
on their online car ads might purchase a copy of J.D. Power and Associates’ semiannual Power Auto
Online Media Study, a survey that gives insights into who buys specific brands and where on the
Web advertisers can find them.11
When the needed data don’t exist or are dated, inaccurate, incomplete, or unreliable, the
researcher will need to collect primary data. Most marketing research projects do include some
primary-data collection.