I've learned that there can be wild variations in quality between some locations of a chain and others, and that you can feel a bad one the moment you walk in the door and have to fight to retain your objectivity for the entire rest of the visit.
I've learned that a restaurant chain that's been in bankruptcy for four years, has awful food and 2-star service (out of five) on Yelp, coast to coast, inexplicably has a shopper program.
I've learned that most bartenders are honest and that the dishonest ones can be outrageous in cash mis-handling. I've learned that Western Union clerks, almost universally, are personally concerned that you are being scammed if you cancel a money transfer, and want to stop you from being taken advantage of...Particularly the ones in the small barrio markets. I've learned the opposite about the clerks at payday loan outlets. Those people don't care about anyone.
I've learned, as noted so much by others, that chains that have a shopping program have much more consistent quality and customer service than the ones that don't.
Doing my best, every day