Apple's Hidden Social Network

I don't really understand this:

> Contacts (Profiles). You can set up name and photo sharing in Messages in two ways: either sharing automatically with contacts (i.e., “following” style social graph vs. bidirectional “friends”) or as one-off events.

When Path was shut down, a shared album became the default social network for my family. I now have one for different friend groups. It's not spectacular, but it works and privacy is the key feature.

> Where does Apple’s Social Network go from here?

Isn't it there a problem that their market is limited by hardware? Outside of the US I feel they might struggle to gain much traction.