You stop by a shoe shop on the way home from work. The shop assistant smiles, says good evening and asks you what you are looking for. You browse the shelves, try 2‑3 pairs and buy one of them. He asks you if he can help you with something else. There is nothing on your mind, you pay for your shoes, and go on your way.
You stop by a shoe shop on the way home from work. The shop assistant greets you by name, in fact he immediately starts showing you the available shoes in your size only. You try 2‑3 pairs and since you are regular, he shows you 3 additional pairs you might like from the new collection. You thank him and while paying for your new shoes he recommends using shoe protection spray for the current weather. He also mentions he can send you an email or SMS when other pairs will be discounted, if you’re interested.
There is nothing wrong with the first situation. You paid for what you expected and got exactly what you required. Everything worked fine and without any problems. Even the result of the purchase is the same, but the second experience feels somehow… better.
On top of that, you are much more likely to keep coming to that shop to fix your new “shoe situation”, aren’t you? Or, even buy the promised discounted shoes that you have already tried on.