As marketers zero in on mobile and social media for the coming year, it turns out that one may be benefiting the other, according to a new report from Nielsen. In July 2012, Americans spent 32.7 billion more minutes accessing social media sites than in July 2011. More than half of that consumption growth (18.9 billion minutes) was derived from additional time spent visiting social media sites via the mobile web or mobile applications, as consumers devoted 30% of their mobile time to social networks. That compares with 20% of PC time spent with social networking – with an astounding 17% of total PC time spent on Facebook. Read the rest at MarketingCharts.