There are a few ways to find your event organizer's contact information:
1) Check out the event's website to see if they provide any contact information.
2) On the EventSprout registration page, there is a "Contact" button on the left informational side bar:
3) Lastly, and if you already bought your ticket, you can find the organizer's contact information by logging into your EventSprout account. Click on the applicable event in your account and hit the "contact" bottom on the right hand side.