Why do I need to upload my attendees' emails?

When you upload your attendee emails, this serves to authenticate your attendees into your event on the app. When they sign into the Whova app using the email you have listed for them in your attendee list, the app will recognize that they belong to your event and enter them immediately. If you do not upload their emails to your attendee list, then when they login to the Whova app they will not belong to an event. In this case, they will need to search your event and enter in the Invitation Code to access. 

Also by uploading your attendee emails, you are able to invite them to download your app once it is published.