The actual form itself is useful and once you’ve set wordpress to use an smtp plugin, invites do show up in email inboxes. But the widget forces double-action, entering emails in the widget box, then again in the form as they are not passed to the form. It would be nice to have a shortcode directly to the form, so that I could make my own sidebar text box using the shortcode to encourage members to invite their friends. I’d rather the sidebar go directly to the form, than force users to enter emails twice.