Google Official Blog:
More than 170 million people have upgraded to Google+, enjoying new ways to share in Search, Gmail, YouTube and lots of other places. It’s still early days, and there’s plenty left to do, but we’re more excited than ever to build a seamless social experience, all across Google.
They must understand that the point is not how many people signed up for Google+, but how many of them are actually using it everyday.
That’s the only thing they should care about if they wanna have any chance to fight against Facebook.