How Do People Decide
Put simply, people buy the brands they want. Not the cheapest. Not the best. Not the most purpose-driven. And so on. Ask why, and the answer is different. Think Apple. Qualitative research (real conversations) will tell you what people really think. Surveys will tell you what they want you to believe.
The right research can help you understand and find better answers.
Read the HBR story: Customer Surveys Are No Substitute for Actually Talking to Customers.