When conducting market research surveys, what type of data do you believe is most important to collect?

There are a plethora of opinions out there regarding what a market research survey should include, how long a survey should be, and how to ask customers to participate. Share with the interviewer what you feel makes up a useful market research survey.

"I like to keep surveys short and sweet, and offer an incentive for completing the survey. Demographic questions are a must, such as age, location, and profession for instance. Then, I will include buying pattern questions such as how long they take to make a buying decision, and how often they shop online. Next, I ask a question or two on what motivates them to make a purchase."