Best Practices for apps.facebook.com pages

[SWKurt]

A client of ours has experienced a large drop in traffic (per GA) from apps.facebook.com referral source in the last 30 days. After a lot of searching, its apparent that there is not a lot of chatter on this topic. So this is a twofold topic.....

1. has anyone observed a drop in apps.facebook.com referrals lately as well?

2. does anyone have any best practices learning on optimizing these pages? Facebook guidance and content in general on the topic is virtually not existent. Google is still clearly indexing the url structure so its visible in search at least.

https://www.google.com/#hl=en&sclient=psy-ab&q=%22apps.facebook.com