7Who do they buy from today, if not you?
Name them. Three if you can. "Nobody" and "I don't really have competitors" are almost never true — doing nothing counts as one of them.
8Why you instead of the ones you just named?
Not "better service." Something a customer could actually check before they buy.
9Who else already sells to that same person?
Not a competitor — someone who sells them something different. These are your best referral partners, and almost nobody asks.
10What would stop them from buying?
Price, timing, trust, habit, or the person they already use. Name the real one.
11What have you already tried that did not work?
Be honest. The thing that failed usually says more than the thing that worked.
12What would one hundred of these customers be worth in a year?
Rough number is fine. If it is not a number worth chasing, you may be aiming at the wrong customer.