Facebook had just launched a beta version of the new Notifications API for apps on Facebook.com that enables Facebook application developers to send short, custom messages to their existing users through the Facebook notifications jewel.
Just like sending Facebook AppRequest, we can send notifications to any existing user that has authorized the app. No special or extended permission is to required. When a notification is delivered, it lights up the user’s notifications jewel on Facebook and appears in the drop down.
If you ask what are the differences between sending notification, sending fbAppRequet and publishing a wallpost to user’s or his/her wall, my view:
- User can send Facebook AppRequest to his/her friends that has not yet authorized our apps. So, Facebook AppRequest can be acted as some kind of invitation.
- Notification is more direct and supports templating
- Wallpost is more suitable for publishing story-like post/information that may include picture, message caption and details. It may be useful especially if you foresee that user and his/her friends are further interactive on the wallpost via writing comments. Yet, publishing wallpost requires the publish_stream/publish_actions permission
For more details information on the notifications API, see Facebook documentation HERE.