Invitations are one of the best ways for users to share applications they love with their friends. Many developers have told us that this is one of the biggest ways in which their applications reach new users and grow usage.
Tonight we're introducing a new feature to make it even easier for users to share applications with all their friends, including those who may not be Facebook users already. In the friend selector as shown below, we've added a new link for users to invite friends who aren't on Facebook. Any invitations sent through this flow are not counted towards allocation limits. To simplify this page for users, we have also consolidated the tabs and different views of friend lists and networks into a dropdown menu.
When a user invites friends who aren't on Facebook, a special email is sent which invites the recipient to the application and become friends with the sender. When the recipient accepts the invite, they are taken to a special Express Registration page to sign up quickly for Facebook and to the application. Once that user joins, they automatically will have the application bookmarked and the application will be promoted on the new user's home page.
Please note that this feature is available with the fb:request-form of multi friend selector for sending invitations. This feature currently applies to invitations only, not requests. (invite=true with fb:request-form)
We hope you'll enjoy this feature and that it brings lot more friends to your applications.