To me, Google+ isn’t so much a social network in the traditional sense or a direct competitor to Facebook.
Google+ is the social wrapper around Google’s existing products, enticing users to spend more time on those sites, interact more and give everything that Google does a social dimension with a cohesive wrapper. I now use plus.google.com as my launching pad to the Google world. This is why I think Google+ is going to be a success.
It’s not a social network in the Facebook sense of connecting with family and friends. Nor do I think Google+ would find much success being a direct Facebook competitor. Rather I see it as Google 2.0 (or a plused version of Google, if you will) that is bringing social to all of Google’s products.
I use Gmail as my main email client, Google Search as my only search engine, Google Docs for much of the work I do here and elsewhere and sometimes I use the Google Reader Web interface (strongly prefer Reeder). Because of Google+, I have found myself using these products more, and this is Google’s ultimate goal.
Google+ is not an island.
If Google wanted Google+ to be a social networking island, I think it would define success much differently. To be a success that way, Google+ would need to rival Facebook in the number of users. But as a social wrapper around Google’s core products — a way of taking Google into a new decade and phase in the company — its core mission is to get people to use Google’s other products more and more collaboratively.