As one psychologist puts it, it is the WOMBASSA - what you think you are going to get and what you do not get when you get what you want. Now, extend this argument to your friend's gift. If you buy the bottle before you visit the guest house, you are more likely to buy an expensive wine. Why? You look forward to having a great time at the guest house and want to express your feelings to your friend. If you, however, gift the wine bottle after you come back from the guest house, you are more likely to offer a less expensive bottle. Why? You did not derive as much as satisfaction as you thought you would.
TEMPORAL ASYMMETRYBehavioural psychologists call this temporal asymmetry. This behaviour may have important implications. In one study, psychologists found that people demand a higher compensation for the work they will do in the future than for the work that they did in the past! Likewise, another study found that a court is more likely to award lower compensation for a victim who has suffered an accident in the past than for a victim who is likely to suffer in the future.
We typically tend to value the future more than the past. And what does that mean to you? If you run a business or offer professional services, receive your fees up front, if possible.