It enabled developers to send data from servers to Android applications and Chrome extensions.

When an application registered for C2DM messages and data, it received a C2DM Registration ID from the service.

This identifier was typically sent by the client application to a server owned by the developer or creator for tracking and statistical purposes.

The third party server then submitted both identifiers within the final data request to be enqueued and sent to the device.

The migration also required changes to be made on the third party server operated by the developer (depending on the complexity and use case regarding the data sent).