No one - and I do mean no one - is using Google's social network, Google+. (Well, Google employees do, but that is a punishment rather than a choice.) One might think Google would simply give up on Google+, but its other divisions have found a use for it.
Google's "My Business" team is responsible for getting businesses listed in local searches, and they are now pushing businesses to add blog posts to their listings. They announced the new initiative back in June (in a blog hosted on Blogger, oddly enough):
With 82% of people turning to search engines to find local information,1 your Google listing is the ideal place to showcase what is unique about your business. Even when customers know exactly what they're looking for, they still want to get to know the business and see what it has to offer. That’s why Google My Business is bringing Posts to local businesses — an easy way to help attract new customers and build relationships with the customers you already have.
The "My Business" listings aren't technically on Google+, but looking at the URL and at source code on the page tells us that MB uses a lot of the same code base.
Google is essentially using Google+ to build the "My Business" blogging platform while keeping it a completely separate service. They've utterly ignored Blogger, the blogging platform they bought in 2003.
That is not too surprising, given that Google has ignored Blogger since about 2011, but it does raise the concern that Google is going to kill Blogger.
Google has now decided that Google Plus is the future, which means they have no use for Blogger.
After all, why would it need to keep two blogging platforms around? Why not kill the legacy platform running (unprofitably) on outdated code?
P.S. I wrote a short guide to backing up a Blogger blog. It is essentially the same as the first steps for moving a blog off of Blogger, and is a good place to start. Do let me know if you need more help.