Direct sharing is the concept of setting up applications to share activities based on the user’s actions, with that user’s knowledge and consent. The user gives consent when she accepts an option to share the application, asks for help in an application, or promotes some goal or accomplishment she has achieved in the application.
The main reason why implementers employ a direct sharing mechanism is because the user is aware of the actions that the application is taking on her behalf, and is therefore less likely to either turn off (hide) application sharing (via the container or application configuration) or to uninstall the application because she feels her trust has been violated. Maintaining this trust relationship is very important when you are trying to build a community around your application. You want users to feel confident that they can use your application without having it do things that they view as malicious or unwarranted.
The biggest disadvantage to direct sharing is the number of activities that will be produced by the application. Unless the application is set up such that it strongly encourages a user to share an activity, many users will not wish to post activities to their streams, which would promote the application to their friends. Social networking container users have quickly become disenchanted with the flood of application activities being posted by their friends. And because most containers provide a mechanism for users to block application ...