The post does what the title says on the tin.
…Here are 4 key tactics on how to utilise Google+ for SEO:
1/ Social Sneezing
a good way of spreading your link bait out to certain demographics e.g. whilst Google+ resembles a wasteland at times it can be good for hitting press, tech geeks, digital marketers, etc. Basically Google+ sharing (as long as you have connected with enough relevant and engaged influencers) = cool
…Google+ is also good for immediate sneezing i.e. url’s that are shared are crawled almost instantly
2/ Increase Follow links
Embed follow links directly into your Google+ posts as then when your posts are shared (again as long as you have enough relevant, influential and engaged people in your circles) it will increase the number of follow links to your promoted content (and what do links? = Prizes)
If someone is following you on Google+, or follows anyone who +1 the content, there is a much higher likelihood of seeing your posts in Google SERPS
This goes for the blood brother i.e. author tag (and this development isn’t knew as my 2+ year old post shows) in that not only can your posts appear higher in the SERPS due to personalisation but playing ball with Google’s social layer can significantly increase CTR from the SERPS as well.
4/ Future Hummingbird shenanigans
Part of Hummingbird (aside from improvements in processing natural language queries; particularly via voice search) was for the mighty G to better process signals other than standard inbound links. e.g. links from social platforms.
An extension of this philosophy is something I documented in my SSP (Social Standing Personalisation) post; that Google will hone in around signals that tell Google if your site/ content is a recognised quality authority in your vertical.
The SSP post goes on to talk about Google using YouTube engagement, those sites bookmarked to Chrome, Authorship, Site KPI’s (bounce rate, time on site, depth of visit, CTR from SERPS, conversions from http to https), etc to ascertain if a site should appear higher in the SERPS. Surely then in the future if, on Google+, you share lots of content, add thoughtful & engaging commentary, your posts receive lots of +1’s/ shares, etc then this will form part of SSP and thus aid rankings.
If you would like to further understand Google+ then use http://www.circlecount.com/ for reports and analytics e.g. daily follower growth, post virality and how you rank against other Google+ profiles.