Pros and cons

With both types of market research, there are positives and negatives to them making secondary research more useful in some areas than primary research and vice versa.
Pros of Secondary Research
+ Often obtained without cost
Good overview of a market
+ Usually based on actual sale figures, or research on large samples
Cons of Secondary Research
 Data may not be updated regularly
– Not tailored to your own needs
 Expensive to buy reports on many different marketplaces
Pros of Primary Research
+ Can aim questions directly at your research objective
+ Latest information from the marketplace
+ Can assess the psychology of the customer
Cons of Primary Research 
 Expensive: £10,000+ per survey
 Risk of questionnaire and interviewer bias.
 Research findings may only be usable if comparable backdata exists.