A few months ago I received an email (above) from US Bank where I’m a long, long-time customer. It was a simple request for my opinion on the bank’s products and services. I was slightly put off by the wordy intro, which concluded with a 31-word sentence telling me how important my opinion was. But that’s just the editor in me. As I was about to press the Begin Survey button, I noticed that I was about to enter a 25-minute questionnaire hell. That was all I needed to know, I left it undone and went on to other things.

Twenty-five minutes! That’s just too long for any normal customer. Ideally, keep online surveys to 5 minutes at most or you risk losing the attention and thoughtful answers of your respondents. If you really need a half-hour of your customers’ time, provide some type of thank-you gift, even if it’s just a chance to win $500. Otherwise it’s almost insulting to ask for that much time with no reciprocation.

Bottom line: While you are not going to lose customers with a lengthy survey, you probably won’t get valid results due to so many dropouts. But you most certainly will irritate a good portion of the recipients. Don’t do it.