Facebook is screwing developers of FB-integrated applications, wiping out their value overnight.
There are two main channels that a Facebook app can use to communicate with users - the Requests Dialogue and the Notifications API.
Notifications allows an app to send a message to be picked up in the notifications jewel by users that have installed their app. These notifications can be generated by the application itself.
Requests are initiated by a user, using Facebook UI Dialogs, and can be sent as invitations to non-users of the app. Requests also show up in the notifications jewel.
Facebook has turned off the Requests functionality for apps that are not labelled as games, breaking many live apps.
This means that an app that is built primarily on the Facebook platform for friendship and notifications functionality cannot now notify a potential user that their friend has invited them to that app.
Many developers use Facebook as an easy way to easily inject social functionality into their applications. Many apps rely on these Requests to grow their user-base. The apps are crippled without Requests.
Facebook want to encourage an eco-system of developers - but when one of the primary functions of a social interaction is yanked with no notice then many developers will question whether the risks of developing on the Facebook platform are too high.
The first bug reports were submitted to Facebook over a week ago - Facebook's response was to mark the changes as by design, saying:
At Facebook we run lots of tests to determine how information can best surface to users.
Our current tests are looking at the impact of reducing the number of notifications we spend for app requests to non-game canvas apps. No other app types are impacted right now. We are close to concluding these tests and then we need to make some decisions. If we have a change that will permanently impact these apps, we will make sure to give everyone a heads up with enough warning.
For these test there was no warning. Advertising campaigns have had to be suspended. Many apps are now effectively useless.
So this is a warning - develop for the Facebook platform and run the risk of your business losing its whole value over-night.