Google+ is billed as the largest social network in the world. However, that is because Google counts every person who signs up for a Google email address as a user, even if they are not actively using it. But, Google+ is so much more than a social network, it's a way to identify and connect with people all across your web activities including search, maps, YouTube and other Google products with just one log on.
It can be hard to determine how many truly active Google+ account holders exist, but it's somewhere around 343 million active users. Facebook still leads, with over 1.15 billion users, and even Twitter has more active users at over 500 million, it's important to remember that Google + is not trying to be Facebook or Twitter. Google is still trying to be a search engine, but it's using all their other products such as Google+ to return better, more relevant and personalized search results. Once you learn how everything is interrelated you can truly begin to leverage Google+ to grow your business.