Sociological Research..what do you think?!?

Question

A few years ago a leading soft drink company was losing its percentage of cola sales to a competitor. To counteract this the company conducted taste tests and asked people all across the country, "Would you prefer a sweeter cola?" 85% of those who took the taste test preferred the sweeter cola. This company immediately spent millions of dollars to introduce the new sweeter cola. A raging success? Hardly. The product was a big flop! But why? 85% of the people who took the taste test said they preferred the sweeter cola. What was wrong with the research?

Answer 1

If they actually posed the question, "would you prefer a sweeter cola", the testers already tainted the study - the samplers may have been predisposed to answer in the affirmative.

Also, maybe the location of the taste tests affected the results.  Did the location have a higher percentage of people who prefer sweets?