How many times have you received a bunch of flowers or some gift that you neither needed nor wanted? People need a source for gift giving that they can be sure of will be loved and appreciated by the recipient.
People like giving a gift that communicates that they put a little extra thought into the gift giving process. No one likes to look like the person that bought the first thing they found at a large impersonal department store. After all, it's easy to get the wrong color and size in a sweater.