The ease of use, reliability & quality control options. I can easily setup my polls with very little knowledge in polling software or computer programming/electronics. My clients have come to rely on its accuracy as well as how easy it is for me to manage their campaigns via this platform. There are some features that could be improved but nothing too major! As stated previously, we've been using GRASS VALLEY since 2009 when they first launched. With them there has never once had an issue where our poll results were off by more than 1-2%. Their customer service team also always responds quickly (usually within 5 minutes) if you need help solving any issues related to your account. We currently only do online surveys which makes managing all aspects of the campaign extremely simple.