Maybe it sounds a little bit nerdy, but I do like Carrefour because there I can spend my time discovering new products, new packaging, as well as comparing different brands. Moreover, these reasons also move me away from Mercadona (even knowing that could be cheaper), because I got bored and forced to buy always the same awful soviet-looking Hacendado products.
Nowadays, I have found another reason to remain in my decision: the single queue. I consider that queuing is one of the biggest wastes of time, and I have thought many times about how to create a queue system for fast people; people who only want to pick up their products and pay without discussing the prices, socializing with the cashier or searching for the perfect shopping bag layout before leaving the supermarket.
In the multiple queue system I am the typical customer who spends his time in thinking about whether I choose wisely or not, and wondering why the fortune has given an advantage to a customer who has arrived later. For that reason, I always try to take an advantage moving from queue to queue, which in most of the times means more waste of time, as clearly shows the following video:
In my opinion, the single queue seems to be long but gives its user the feeling of constant progress, as well as guarantying that any difficult customer will not stop the others. Also, it is fair for everybody: all customers and all cashiers will wait and work the same time respectively. On the other hand, I cannot avoid the pleasure of hearing everybody complaining about the length of the single queue, knowing that they are wrong.