We have been working on Google Plus for 6 months now and we have picked up over a hundred back links from Google in the last 6 months that the experts are saying will ultimately give us some benefit in serps. I do know that in the G+ community we are in
https://plus.google.com/u/0/b/113851995878848732706/communities/116014967343607280698 there are several individuals who in the last 6 months have gone from oblivion on page 2/3 to a good position on page one for respective search terms for their business domains and they attribute this to a good presence on Google plus which unlike facebook, twitter and forums whose links are no follow, some of the Google links are followed which means Google are giving some domains link juice so its a no brainer any one wanting to grow their business should be there taking advantage of Google Plus that gives direct access to their search engine that controls 82% of the internet.
It is essential to have a business profile that links to a personal profile who is a real person that builds a presence through authorship that subsequently Google will treat you with some preference as opposed to the the shady anonymous entity's who are deploying black hat SEO practices. Thats where I think the guys I know on Google + have done well because Google is already acknowledging authorship and applying the same to the businesses linked to the owners in there algorithms.
Check out this post
https://plus.google.com/113851995878848732706/posts/2E3Je3oPJroThis Guy Jeffrey Tobian has achieved amazing things with Google plus in just 1 year...! look at the number of views he has had over 700,000 ....!
And more importantly on his website the Google plus counter shows over 7,800 people have plussed his page that knocks Facebook into touch
regards promoting our cleaning business