For SEO it's worth creating a business page for your business/website and linking to it via your website (using the meta tag, as Google suggests) to verify your page's ownership. Other than that I've not seen much use for it.
As we know,more and more people use google plus,facebook,twitter promote their product..... I usuuslly to use google plus to promote my product in the future but now I just want more fllowers first.
I'm also using Google plus for my blog promotion and it really works. You must try it. Share your posts, create and expand circles. Join Google plus communities and see a difference.
Google Plus is a good social network. I use it to advertize my products as it gives me handsome amount of traffic.