I needed an easy way to follow and interact with students in my courses.
I didn't want to forcibly mix two streams of content, one student oriented, the other not at all.
I find it hard to easily categorize people into circles. Better to let them choose the stream they want to associate with. Making everything public lets people make informed decisions about engaging with you. They can see it before they make the plunge to circle you.
It's much easier to just switch into a completely different persona for particular tasks.
The teaching profile attracted quite a few followers (several thousand). People seemed to want that kind of content.
The strategy behind the teaching profile was haphazard. I only attempted to connect with students but put no time into thinking about what the appropriate external connections would be.
I was influenced by +Guy Kawasaki's dictum to use Google+ as the blogging platform for a book I'm getting to work on (by the way, his book on publishing is very worth the $10 price on Amazon or other electronic outlet).
Therefore, it made sense to create a profile focused on moving my teaching and book writing efforts forward (they're joined at the hip).
+Joseph C. Miller, +Shawn Drape, +Thomas Morffew, +Ade Oshineye, this post is for you.
Finally, I still find my original profile quite useful. I'm not abandoning it. I'm just creating a new focused line.