The Progress Bar
We are starting to see a widespread adoption of the progress bar game mechanic to motivate user behaviors. LinkedIn has been doing this for a long time. Facebook games are now using it to motivate players to bookmark and fan their app, since in a post-notification world that allows the game to communicate with the player more easily. Finally, a number of new non-gaming web startups (like Homerun.com) are using the progress bar to take users through sign-up and profile creation.
