I will respect the findings of the studies quoted above and definitely a lot of research would have gone into the findings . And yes ofcourse "make clear what you’re encouraging the customer to do, but don’t come across as manipulating them into doing it" is a very acceptable conclusion indeed.

However I would like to point out that not so much in the distant past probably around 2 years back or a little more, a major retailer in US suffered a lot of pain ,a good % loss of actual loyal customer base from their stores happened due to reversal of store discount schemes and the attempt by senior management to establish a different pricing scheme. If my memory recollects well , it actually resulted in the removal of the CEO.

I do see above that the selective set here is "major European book retailer" but on the North American side looks like coupons and discounts are still working from the perspective of footfall volume and amount of sales generally reported by the stores when there are those days across the year when the concentration of these incentives are high.

Thanks for the article , a good read and a valuable perspective. Wanted to share my 2 cents too of the other side of the river.