Social is becoming visual, this much is clear. But how much of an impact are visual networks having on the overall picture? We’ve already noted that Instagram and Pinterest are the fastest-growing social networks on a global scale, and now new research suggests that might be at the expense of more established sites, such as Facebook.

Data analysis company Compete has published some interesting findings about Pinterest’s growth and its impact on marketers, revealing that as the scrapbook site has grown from 700,000 to 20 million unique users in the past year, one in four users say they spend less time on other social media because of it.

Indeed, Compete attributed a 3% decline in Facebook activity in June this year to pinning preferences.

The research has also thrown up some key social commerce findings, which brands wary of Pinterest would do well to take on board:

• A quarter of consumers (25%) reported purchasing a product or service after discovering it on Pinterest, rising to 37% among men.
• Food related content is overwhelmingly popular on Pinterest, with 57% of consumers interacting with such media. It’s no surprise, then, that outbound traffic to relevant sites was up: traffic to Allrecipes.com was up 16%, and Kraft’s recipe site enjoyed an additional 4% share of Pinterest’s outbound traffic in May.

View Compete’s full data here.