Sadly, many social networking containers are usually oversaturated with applications from their galleries, causing them to relegate applications to undesirable locations to prevent many of their core social features from being overrun by application windows. This raises a major problem for application developers: if your applications are being placed on subtabs or other less-than-prime locations in the container, how will they be surfaced to new users?
One of the best methods you can use to encourage user growth in your application is to promote it through the user’s activity stream. The activity stream is one of the few gateways to users that developers can still access if a container does not provide prime real estate for application windows. When a developer taps into the activity stream by setting new updates that draw the user’s attention, he generally sees a larger influx of users than he would by just relying on gallery installs.
The method used as of OpenSocial 0.9 to push an update to a user’s activity
osapi.activities.create(...). This method allows a developer to quickly output a message from an application to an activity stream or any available activity consumption channel provided by ...