Member variables allow you to create custom fields for your members.
Examples of member variables can be anything. They can be a spot for a member to paste the embed code for a video, a place for them to put their payment details, a spot to put their username for another program, etc. The values an member puts for their member variable can be displayed on their capture page, in autoresponder messages, and in the members area. You are able to add an unlimited amount of member variables.
To add/edit/delete member variables go to "Manage Member Variables" (your-domain.com/admin/membervariables) while logged in as the admin. Member variables added by the admin at the "Manage Member Variables" page appear on the members Profile or Settings page.