Haven't posted publicly at least.

This is exactly right and the title should really say that.

Yep, it would be nice to know how many posted at all. I guess it's not publicly available data ;-)

Of the "48%" (since there are some questions about the number), I wonder how many are cross posting to Facebook.

I'm one of them. Won't bite until it allows me to import my Twitter feed.

did you want the contacts from your twitter feed? or just to feed your posts from twitter to g+.

If its just the contacts you wanted you can go here: https://plus.google.com/u/0/settings/connectedaccounts?tab=X... and connect your twitter account. (I am pretty sure this will drive the 'suggested people' page on google+)

I also found this comparison of cross-posting tools:

http://techplugged.com/2011/07/29/link-and-post-google-plus-...

My posts.

More Than Two-Thirds of Google+ Activity Is Private: http://allthingsd.com/20110721/more-than-two-thirds-of-googl...

It's designed mainly for private sharing hence the circles.

If that's the case then 52% public posts is a lot, right?