The author offers opinions on the use of Internet surveys in marketing research. A threat to the accuracy of such surveys is said to exist in that persons who participate in online survey panels tend to be much heavier users of the Internet than other consumers, meaning that their answers to questions on mass media use or shopping behavior can skew survey results. It is stated that that can lead to poor decisions in advertising media planning based on a perception that consumers on average spend more time on the Internet than they actually do.