The few Mintel shops I have done are for a MAJOR credit card company...these shops were around large conventions. I have spaced them at least 6 to 9 months apart, as the same reps seem to be at all of the conventions and these are targeted shops with a list of "Don't shop these resp."
TIP FOR MINTEL SHOPS: The above shops I mentioned...in the debrief, Mintel want us to UPLOAD the pages with our notes...the questionnaire we print out, about 15 pgs...since I audio record my shops, the first time I had to scramble to scribble notes on all of the pages. Second time I was prepared, but still had to put notes on the pages for the debrief.
Hope this helps someone...Hugs