Experts call this kind of information about your business qualitative research. They advise against trying to get percentages or firm trends from this kind of research. Use it strictly as a source of ideas for what might be.
Use customer comments to point out POSSIBLE problems or opportunities.
Just because three people email you with a complaint doesn't mean that a big chunk of your customers feel the same way. You will have to dig deeper with a website questionnaire or random emails to customers.
Pay close attention to how people's opinions and actions differ. For example, people who work in media will tell you audiences often watch programs they say they don't like. We asked a group of radio listeners if they liked Madonna and all said they detested her. Yet, when we played a Madonna song without mentioning her name, they marked it as one of their favorites.
