I'd rather not have my purchases/interests being broadcast to my "friends", thank you. What are these "friends" anyway? Everyone in your contact list?

The last thing when buying an app I want to do is to worry about "What if X sees that I got this app?"

My purchases are my business. Not theirs. If I want to recommend an app I can do so through a variety of way in this communication age. I do not need some automated snitch for that.