Smells, nice or disagreeable

I am reading the Italian translation of Stasiland by Anna Funder, published by Edizioni Feltrinelli, about the GDR before the reunification and the infamous political police of the former East German regime, whose records are currently accessible.
A section of the essay deals with smells. In a wing of the former Stasi building in Leipzig, in fact, they still conserve rows of sealed jars containing scent samples from GDR citizens, collected by using clothes, biological finds and other means. They were used by specially trained police dogs in order to identify the actions of political dissidents.
Smells constitute an often underrated aspect of cognition; there is a branch of marketing that investigates this phenomenon.
Scent marketing, which forms part of sensory marketing, relies on the use of fragrances developed with the aim of fostering different emotions in people, influencing buying behaviours (by increasing dwell time ad impressing the memory of a pleasant experience) and associating a name or brand with a particular scent.
This type of approach is quite suitable for hotels, which are both a place and a product (avoiding the risk that scent only evokes the one, and not the other), and is embraced by some. In Milan, for example, an important hotel owned by perfumers spreads various fragrances in the common areas and guestrooms. In my opinion, this is a doubtful use of the tool, because the variety of aromas detracts from efficacy and confuses the guest’s memory.
Personally, I do not at all appreciate the overlapping of different fragrances, that is why among the places I enjoy the least are the ground floors of (more ore less luxurious) department stores, traditionally hosting a great number of perfumery products in a mêlée of scents.
On the contrary, I like the policy adopted by Casta Diva, the resort on Lake Como, which has identified an excellent fragrance as leitmotiv throughout the entire complex, to the point that the car valet will spray some inside the car of a guest at the moment of departure. A good way to prolong a memory, and a sound marketing practice