Some have argued that service after the sale is where longterm relationships are made or broken. Good customer service is so important to people, in fact, that some companies can get away with charging more than what their competitors do because of a reputation for great service.
Take cell phones, for example. A lot of us are simply lost without them. Let's say Company A and Company B both sell smartphones that are similar in features, but the one from Company A costs a bit more because it has a reputation for offering great service after the sale whereas Company B offers one of those "mail it in and we'll send a replacement" things. In that instance, Company A's customer service is the deciding factor and the thing valuable enough to pull in a premium price.