We have added new useful feature for adding custom fields to registration form for Affiliates and Advertisers. Only Administrators can manage this feature. 

So you need to login under administrator account, open Tools tab, click on Application Custom Field tool

Example:

You will see the next screen:

Example:

Click Add Custom Field to add new custom field or Edit button to edit selected existing custom field. Also you can delete existing custom fields.

Example:

After adding custom fields under Administrators account open Sign Up Application Form to be sure that everything looks correct.

Example: