I work for a company that does online surveys. If anyone is going to complete your survey, it is me. However, as I look at my inbox and see 35 emails that I need to respond to, a promise of a “short survey” rings untrue. Too often a ‘short survey’ is promised and then 20 minutes into the survey you are only halfway done. Boo. This dark promise has ruined it for the rest. If your survey is truly short, tell them exactly how many questions it will be. This is believable. Keep it under 7 questions.