Comment cards have multiple problems, but one that dawned on me recently is that most customers will not go through the trouble of filling out a comment card unless it is something they really want to express.
In our recent article about the different types of online reviewers, we outlined that when someone takes the effort to write a review online, the majority of the time the review will tend to the extremes, either positive or negative. Yelp will typically filter out positive "first time" reviews because they look fraudulent. If a brand new user to Yelp writes a glowing review, Yelp assumes it is someone the business is paying or associated with.
This behavior is consistent with comment cards. When a customer takes the time to fill out a comment card, they usually will not go to the effort if their experience was "just OK" or there was a tiny complaint. They will fill out a card to rave about excellent service or terrible service. It's the good old 80/20 rule.
20% will fill out a comment card on the extremes of excellent or terrible, but the other 80% of your customers won't take the time because the comments they have are "not worth it".
So what you miss out on are the 80% of customer's thoughts on what you are doing well, and what small to medium things you can do to improve.
If customers are given a convenient way to give feedback that only takes a few seconds and little effort, you will get more feedback that is across the spectrum, giving you a better picture of your business and the customer's perception.
We invite you to take a look at TalkToTheManager, the easiest way to get real-time, honest customer feedback.