WordPress User Registration Aide Force & Add New User Fields on Registration Form, as the title implies, allows you to force or require more fields when a new user registers. This not only can help to stop spammers, but it can also increase your user management capabilities and services. All the new fields that you add will also be added to existing users profiles, but the users will have to fill them out of course, but any new users will be required to fill out these fields giving you more control over who registers for your WordPress site.
Another important option is that you can also add new fields but not require them for registration, so you can increase you user management capabilities. This is an exciting new feature for Webmasters that wish to increase contact options, communications, and information obtained from your user base.