Google Plus or Google+ is a new social network that was created to compete with Facebook. Even though it's not as big as Facebook or Twitter yet, it is growing rapidly. Plus there is so much free traffic on this social network that is actually targeted traffic, instead of traffic from Facebook and Twitter which has the most visitors but may not be interested in your product.
The best way to utilize Google Plus is to join communities that are related to your niche. Join as much as you can and post on their page (without spamming of course). You can also start your own community and let others join and post their ads. The more communities you join, the more of a chance you have to get your product shown. If people like what you post, they will +1 it and when that happens, Google will take notice of it. The more +1's you have, the higher your website gets ranked in Google.
That's another reason why Google+ is becoming one of the best social networks. It is the best way to apply SEO to your website. So create a Google+ page, join communities and post on them. Also you can start a blog like the one you are reading now. Every article that you post on your blog automatically gets posted on your Google+ page. The more articles you post on a daily basis, the more followers you get on Google+. It's very important to get as much followers and Plus Ones that you can. All that traffic for FREE!