The number of publicly reported surveys conducted using automated telephone interviewing techniques, or robo-polls, has increased dramatically over the last few years. Pressured to cut costs, many media organizations no longer commission traditional telephone surveys, sponsoring robo-polls instead. Often the results of different surveys are compared regardless of the mode by which they interviews were conducted. This paper conducts a time series analysis of the President’s job approval question asked on 624 national surveys conducted with live operators, over the internet and using robo-polls. It concludes that while live operator surveys and internet surveys produce quite similar results, robo-polls produce a significantly higher estimate of the disapproval rate of the President and a significantly lower estimate for ‘no opinion’, attributing the difference in results to non-response bias resulting from low participation rates in robo-polls.