Nielsen has released its 2012 Social Media Report and says that when it comes to accessing social content today, it’s all about mobile, especially apps.

Compared to 2011, consumers increased their mobile web usage 82% over last year. The report found that people continue to spend more time on social networks than any other category of website – 20% of their time on PCs and 30% of their mobile time is spent on social networks.

Here are the most visited social networks and year-over-year change:

As the Nielsen report notes, social media has fundamentally changed the consumer decision journey. Consumer decisions and behaviors are increasingly driven by the opinions, tastes and preferences of an exponentially larger pool of friends, peers and influencers.