Editor’s note: David Ensing is vice president, automotive research consulting at research and software firm MaritzCX, Toledo, Ohio. This is Part II of an edited version of a post that originally appeared here under the title, “Improving survey response rates through incentives.”

In Part I, I discussed ways to increase the benefits to consumers who participate in a survey. Part II will look specifically at monetary incentives. 

In most circumstances, to increase response rates I recommend investigating the non-monetary methods listed in Part I before considering use of a monetary incentive (or any incentive with monetary value – e.g., a free oil change or a discount coupon for your next purchase). If not done properly, monetary incentives have the potential to bias the responses.

What makes an incentive appropriate?

Generally, the smaller the incentive the better. This is not only because smaller incentives are more economical, it is primarily because larger incentives have more potential to bias results. There are two main concerns with large incentives. First, as incentives increase respondents are more likely to complete the survey just to get the incentive. Therefore, they may pay little or no attention to the questions they are answering and provide bad information. Unfortunately, bad information is worse than no information at all. Second, larger incentives may bias the sample by encouraging lower income individuals to respond at greater rates than higher income individuals.

One thing to take into consideration when using a small monetary incentive is that it should be framed as a small token of appreciation to the customer. If customers believe you are trying to compensate them for their time with a small incentive, they can become offended.

If possible, provide the incentive to everyone being sampled rather than promising an incentive to those who complete the survey. In the...