I've maintained social pages and accounts for the more popular business ventures and websites I run on Facebook and Twitter for a few years now. These pages and accounts have driven a good amount of traffic to my sites (and they would drive more if I put more time into making them more relevant/personal).
When Google+ announced pages similar to Facebook's, I quickly set up a page for each of the same sites. But since I don't have time to manually post and manage each of these pages, they sat dormant since the day I set them up.
Plus, nobody 'circled' any of them.
Plus, nobody's really on Google+ anyways, besides the regular early-adopter crowd that, like me, jumps from new service to new service just to test it out and see what's neat and what's not.
Plus, Google+ doesn't have a real API that provides any value to me. Heck, I can't even have my site post an update to a Google+ page automatically... that's like feature #0 that should be in the API.
Like a rotary telephone, Google+ is not really relevant.
So, anyways, I haven't really posted much on Google+ in the past few months, and I'll probably end up not posting at all sooner or later. You can still find me on Twitter and Facebook.
Maybe if Google+ becomes relevant, and builds a useful API, I'll come back. As it is, the only neat thing about Google+ that provides any value to me over Facebook or Twitter is the Hangouts feature.