• User Experience: Allowing developers to design applications on top of your platform provides the ability for users to have unique experiences tailored specifically for them. From a mobile perspective there will now potentially be a thousand different versions of the same operating system each tweaked slightly so that it fits the owners needs. Furthermore it will allow people to share the coolest parts of their user experience across all networks.
  
• Standardization: With numerous partners involved in both OpenSocial and Android, developers have a standardized way of creating applications for users without having to worry about platform. The standard platform also helps define documentation, procedures and application sharing.
  
• Cost: Open platforms always tend to be far less expensive than mainstream/off the shelf products. With platforms such as Android in place, users will notice a cut in cost compared to hand helds operating systems like Windows Mobile and Palm OS.
  
• Innovation: Giving developers the access to such powerful and flexible platforms will encourage increased innovation as they compete to develop the next killer application.
  
• Support: Open Platforms (1 common base) equals Thousands of Developers which equals the amount of support available for applications and configuration that are built on top of the platform.

The one thing that might raise some concern is what will happen with the quality of products with the amount of applications that will likely be developed and the power completely in the hands of the users to install them. I would hate to see an uproar due to privacy or security concerns .