There are many customer satisfaction surveys conducted by thousands of companies each year. Some are more reliable than others.
The main difference is before and after. For example, in an election voters in an exit poll (Who did you vote for?) give more reliable answers than voters give before an election (Who will you vote for?).
THE NET PROMOTER SCORE (NPS) is a before question. The NPS is widely used to predict corporate growth by asking this question:
How likely is it that you would recommend our company/product/service to a friend or colleague?
THE WOMBAT QUESTION is an after question:
Have you told anyone yet through word of mouth about your satisfied customer experience with us?
If I remember correctly from my brief stay Down Under a long time ago, the wombat is a badger-like animal, with a poach on its back. Nevertheless, being a private perrson, I think I would be reluctant to share my thoughts, whether before or after a buy. Most likely I would leave a meningless repsonse.
I find the question “How likely are you to recommend our company to others?” most annoying. It was asked recently in a “How well did we deal with your complaint?” survey. “On the basis of our response to your complaint, how likely are you to recommend XXX to others?” The likelihood of this happening is a product of the likelihood of anyone asking me (about 0.001%) and the esteem I hold the companies service in generally. (around 20% as I had the problem in the first place). What do they do with my score of 1/10 because that is the lowest score available? If they want to know if I am satisfied with the way they dealt with the problem, I could give a meaningful answer.
The WOMBAT version makes more sense but, due to the 0.001% likelihood of anyone asking me it would get a zero or as low as possible.