Each shopper is thoroughly briefed prior to the restaurant visit. Each is asked to order three courses, side dishes and a moderately priced bottle of wine. St Kilda's Stokehouse has used mystery shoppers for nearly five years. Eldred's reports, based on mystery shopping, quantify a restaurant's performance in the areas surveyed. Furthermore, these performances can be measured against a market average.
People leave, and they say nothing.
But it is not just large restaurants that value this kind of research. Onions, a small South Yarra restaurant that reopened five months ago, is owned by a couple who have both worked in restaurants using the system. You have to be up to criticism, and anything that challenges you is a healthy thing.