Message from EA:

There is a known issue with the latest version of Origin 8.5 which is
impacting customers who purchased Mass Effect 3 digital download from
retailers other than Origin. During installation, these customer will likely
see a message indicating a disc read error. If the customer simply clicks
Try Again in the error dialogue that should bypass the error and continue
the installation. We are aware of the issue and hope to resolve it soon.
Meanwhile, If the problem persists, please visit help.ea.com.

For most mac games (not EA).

Contact Virtual Programming about this. They have got a problem with their activation platform (Deliver2Mac) and need to handle this manually.

To get Networker, one must go to Account settings -> Facebook connect and make sure to be logged in to/connected to Facebook.

To get Twitterastic, just hit the Tweet button on a product page!

/Ashot