Two business facts:
1. Marketing departments often fail to understand that it costs 9 - 10 times more to win back a customer rather than keep him / her.
2. the number of people who actually complain to a company officially, or via a forum / social networking, are a very small proportion of the total number of dissatisfied customers. That means, most dissatisfied customers simply walk away to another company without writing to complain.
Conclusion:
Astute marketing and customer service departments therefore listen to, and act, to even a small number of complaints because they know the real number of complaints is massively more, moreover, they know it will cost much more to try and get people back.
Enough said.