• by Mark Walsh  @markfwal, July 9, 2014

By now it's clear that mobile and social have become more than a shotgun marriage. Findings from comScore last month showed that more than 70% of time spent in social media takes place on mobile devices (including tablets). And total mobile engagement on social is up 55% in the last year.

In its latest quarterly report, ShareThis took a closer look at sharing activity among top social platforms on mobile. Twitter and Pinterest emerge as the most mobile-centric networks, with 75% of all content sharing on those platforms happening in mobile. By comparison, half of sharing activity on Facebook is mobile.

However, because of Facebook's size (1 billion monthly mobile users), it accounts for 72% of sharing on smartphones, versus 14% for Twitter, and 12% for Pinterest. On tablets, Facebook’s share falls to 64%, and Twitter's to 7%, while Pinterest sees a bump to 22%. “There is a clear preference for channels based on different devices. Pinners are more active on tablets whereas tweeters flock to smartphones,” states ShareThis blog post today.

Furthermore, Facebook is where people go to share content about politics and parenting, while Twitter -- because of its real-time DNA -- leans toward sports and business, and Pinterest sharing is focused on shopping. That’s a natural outgrowth of Pinterest's emphasis on visual presentation and consumer products.

In that vein, mobile users are twice as likely to interact with desktop content as any other category.

When it comes to mobile operating systems, Android users are more active on Facebook, while iOS users are more likely to share material on Twitter and Pinterest. In terms of demographic trends, sharing on tablets among people 55 and over nearly doubled over the first quarter. And 43% of social activity on tablets is driven by people in that age group.

Social interaction on mobile devices also grew 13% among African-Americans and 6% among Hispanics in the quarter. Overall, sharing from smartphones and tablets grew more than 30%, while that on the desktop fell 5% between the first and second quarter. The mobile gain was driven mainly by activity on smartphones, which was up about 28%. 

Across desktop and mobile, Facebook accounted for almost two-thirds (64%) of sharing, with Twitter and Pinterest each claiming 9%. But the two smaller competitors together gained 2% share on Facebook from the prior quarter.