Google, not surprisingly, is going after every core user group on Facebook, from brands to moms to now, teens. Google just lowered its age requirement so teens ages 13 and up can use the site.

Marketing Pilgrim questions the wisdom of this move, mainly because it appears to be a waste of resources on Google's part.  "I do believe that Google+ has many elements that would be helpful to teens, such as the ability to group followers and video chat on Hangout. But the decision to lower the age rage seems a bit premature."

One area Google might be better served focusing on, it said, would be its engagement rates.

Young Adults

Or, another, more appropriate target for Google+ might be the age group one generation up from teenagers: young adults in their 20s.  A study by Millennial Branding show that Facebook users in this age group tend to mix work friends and social friends on the social networking site—an area that Google+ has highlighted with its Circles feature.

The survey said that 82% of Gen Y (aged 18-29) Facebook users have at least 1 work friend, while 53% have more than 5 work friends and 40% have more than 10.