The Hat Tipper said:
It will be successful for one reason: Your parents aren't on it yet.
My parents don't use the internet.
I saw on the news that parents these days like to keep track of where their kids go online to prevent them from talking to untrustworthy people, so it might not take long for Adults to be on Google+.
Plus, Google+ would probably not be just be exclusive to College students like when Facebook started up. Google+ also might get a lot of coverage from YouTube, blogs,newspapers, magazines, and TV News since it is made by Google, so it probably won't take very long for kid's parents to know about G+, and join.
I think older people might be more attracted to Google+ since Facebook now has a lot of teenagers to college kids like when Myspace was still ran by Tom Anderson and not Fox/News Corp, flash games, and groups like "Planking Australia, pop bands, etc" which are mostly for teenagers to young adults while a large percentage of adults in their 40s-50s don't play flash games, care about planking and teenage trends, and don't listen to teen music like Taylor Swift.
Google+ seems more like a competitor to LinkedIn which is a "Employment, Job Networking, and Career focused Social Network for 20 somethings or older professionals who are still working" rather then a "Social Network to hang out and make plans with friends like Facebook, Myspace, etc."