Most successful festivals of any kind (science, art, food, music, cultural, etc) directly generate local economic activity. In 2010 the Science Festival Alliance contracted an independent evaluation firm to assess the impact of festivals lead by MIT and UCSD. This evaluation surveyed more than 1,300 attendees at more than 45 events that were part of the Cambridge and San Diego Science Festivals. This resources shares about the economic impact of Science Festivals and the audience survey data.