It took all of marketing out of it. Those panels had strips with a product name and and LCBO stock number. No 'ooh, that looks interesting'. You had to know what you wanted and I don't remember if there was purchase limit (in the 1960s).
I remember living in small town northern Ontario and coming down to the folks in Scarborough for Christmas. I offered to buy the booze and went off to what was one of the first self serve stores. I was walking around with my shopping cart grabbing bottles left and right until I did some mental math and ended up putting half of them back.