What problem did we help you solve?
What encouraged you to become one of our clients?
What made you happiest about working with our company?
What have or will you be able to achieve since using our service?
What did we do to exceed your expectation when working with us?
What would you tell someone who's considering our business?
Was there anything we could have done differently?
Is there anything else that you would like to comment on or say about our business?