Google+ doesn’t want to pull anyone into a walled-garden the way Facebook wants. Instead, they want to go with us wherever we go. It’s subtle, but it’s clear. Facebook is saying, “come do what you need to do here,” while Google+ is saying, ‘take us with you and let us help you with what you need to do wherever you need to do it.”
via 7 Reasons Why Google+ Will Succeed (and 1 reason why it will very likely fail).
Something similar to Dave Winer’s “People come back to places that send them away“