This delay can be made worse if the account is set up close to the weekend because sometimes data aggregation slows and gets pulled in on Monday. We want to tell Google Analytics that, instead of generating a new client ID when someone goes to Eventbrite's website, it can keep using the same one as before. If all went well you will be greeted with the login page, providing you set a user name and password, which I recommend doing.
If you are using the newer Universal tracking please refer to the docs. Twitter will use this to make your timeline better. See if you are using Classic Analytics (ga.js) or Universal Analytics (analytics.js).