Here's the scenario: you have identified a lucrative new account, one that would help you make your numbers for the year. You want to know why they are buying from your competitor instead of you so you will know how to structure your account strategy. If you ask them, will they tell you why they like the other company?
 
Here are two common approaches: 

1. "Why are you buying from the competition?"
2. "Mr. Customer, in doing my research I found that you are buying from my competitor and I'd like to know why you prefer their offering over ours."  
   

The first approach hits the customer head on - "D's" (of DISC) like that. It cuts to the chase. Will it work better than the indirect approach in the second approach, one that also shows the customer that you've done your homework?
 
It doesn't matter;they are both fatally flawed.
 
People tend to defend when asked a "why" question. It's an interesting quirk of human nature, one that we develop early in life. When someone challenges us with a question asking why we did something, we immediately and instinctively go into the defense mode. We feel the need to justify what we did.
 
When we were kids and our mothers asked us why we did something really stupid, we went on the defense. At first we tried the "I don't know" approach but we were punished anyway. Then we tried various excuses, like "everyone else was doing it" and "he made me do it",  hoping to avoid punishment. Now it is innate behavior as you will see below.
 
The key to whether or not the customer will tell you why they are doing something is how the question is worded. Here's the rule:
 

"Never Ask a 'Why' Question"

It's just too risky - too likely to stir up a defensive response, one that will set back your sales process.