Contrasting that with an online survey, the more passionate you are, the more likely you are to respond. So a so called “vocal minority” can skew the results. The problem is that while they are vocal, if you don’t have a huge response rate (>75%) you don’t know if they are a minority or not. You can correct for this somewhat by doing phone polling at the same time but it’s not perfect. Online surveys are great for getting ideas and long-form feedback but that’s about it.