According to Nielsen's latest Social Media Report, the amount of time that US consumers spend connecting to social media networks not only is huge, but shows no sign of abating.

Published Monday, the report analyzed mobile and fixed internet use across the US during the month of July 2012 and discovered that over 31 days, US web users spent a staggering 520.1 billion minutes online, a 21% increase over July 2011, and of that time, 121 billion minutes were spent on Facebook, Twitter and other social networking sites. All in all, 30% of online time via mobile, and 20% of online time via a PC is spent on social media, making it the most popular online destination.

Nielsen believes this continued growth is due to the proliferation of mobile devices in the US as well as the growing quality and choice of apps available. The PC is still the most popular way of accessing the social web but it saw only a 4% increase in usage, while mobile and app use grew by 22% and 120% respectively in terms of minutes spent online. What's more, as 17% of US consumers' PC time is dedicated to Facebook, it has become the most popular web brand in the US.

And, when it comes to accessing social content, users are moving further and further towards apps. App usage now accounts for more than one third of social media time, across PCs and mobile devices; as such, time spent using social apps increased by 76% compared with July 2011, and while the number of users accessing the social web via a PC actually fell by 5% over the past year, the time spent accessing such sites via a PC grew by 24% over the same period, suggesting that users have never been more deeply engaged in the social web.