Facebook so far has two influential innovations in social apps: mini-feed and open social platform. The mini-feed is a passive messaging system that constructs a social sensory mechanism. This feature is so successful in creating viral effect that it becomes a widely copied feature as well.
The good: the sweet-spot of mini-feed is the social messaging to enhance users' social sensory capability. It makes a lot of sense to be notified that "Nikki and Alan are now friends" and "John was challenged to a movie quiz!". (Beacon and privacy are a separate issue)
The bad: turning the mini-feed into a personal activity log. It happens on some copycats when the copiers missed the point that social messaging is about what happened on other people who are relevant to you. It's not about "I installed this stupid facebook app on Tuesday 9:34pm and found it's actually really fun". What you care about is to share this app with friends, not yourself.
The ugly: making mini-feed overloaded to the users. The feed is bulky and no longer "mini". The worst scenario is it gets quickly spammed and becomes useless. Facebook started to suffer this problem when the user couldn't digest huge amount of social messages mixed with lots of non-sense ads. The obvious simple solution is to limit the categories of emitted social messages and prioritize them. The ultimate solution is to create intelligent agents that will help the user to process and filter the surrounding social messages.
