I would just answer the question honestly. Not always is that question a disqualifier. On a number of registrations I have been asked if I ever worked in the hotel or restaurant industry only to discover that the WANTED people with that experience, or I am asked whether I have ever worked in retail to discover the same. What they are trying to determine is that you do not shop a client where there is a potential conflict of interest. One shopper here used to work at Starbucks. While they should not send her to Starbucks because she would have positive or negative opinions about Starbucks already formed and know their procedures so not be an unbiased observer, sending her to Joe Muggs or Seattle's Best or to evaluate the coffee service at McDonalds should not be a problem.