After event communication

Following an event, it is very relevant to send a thank you note for the attendee’s presence. This reinforces their commitment to your event or organization. At the same time, we also suggest sending them a post-event survey to collect their comments and suggestions in order to improve your future editions. Feel free to adjust the text to your liking. 

When offered something in return, people are more likely to answer your survey. For example, you could offer them a 10% discount on their tickets for the next event of their choosing. It is also more likely to up the number of answers if you put that information in the subject line of your email. 
Example: Get 10% off your next purchase for our events!