I agree it's cute when you first crack this open to think that you have to have a 1:1 mapping between your circles on G+ and what you considers your "real life"

I agree it's cute when you first crack this open to think that you have to have a 1:1 mapping between your circles on G+ and what you considers your "real life" circles to be, however this isn't the case. You just need to break down your circles to be based on the audience for what you share, sometimes this is as easy as "social" and "professional". Everyone lives their lives differently though. "circles are ... less for sorting incoming broadcasts by topic" I disagree with this because streams are linked to circles, so you can easily create a circle for people you follow (like Twitter). You may not want to add these people to your "broadcast" circles. p.s.: You aren't obligated to put people who follow you into a circle. Famous people probably ignore these requests (again, like Twitter).