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, shaped like an envelope, on the right hand informational side bar.
3) Lastly, if you already bought your ticket, you can find the organizer's contact information by logging into your EventSprout account. Click on "View Order" for the applicable event in your account and the contact information will be on the left hand side.