Pinterest, the web-based "pinboard", which launched almost two years ago, barely got a mention until 6 months ago.

Editor’s Note: Pete Cashmore is founder and CEO of Mashable, a popular blog about tech news and digital culture. He writes regular columns about social media and tech for CNN.com.

Story highlights

Unique visitors to Pinterest grew 400% from September to December 2011

Pinterest drives more visitors to third-party websites than Google+, YouTube and LinkedIn

It's a visual social network that organizes by topic and lets you reshare with one click

CNN  — 

Pinterest is the breakout social network of 2012, but even technology addicts could be excused for missing its rise to success.

The web-based “pinboard,” which launched almost two years ago, barely got a mention on Silicon Valley news sites until six months ago, when early adopters suddenly realized that a site with millions of monthly users had sprung up almost unnoticed by the tech press.

That’s because Pinterest didn’t take the usual route of Web-based startups: romancing early adopters and technology journalists before attempting to “cross the chasm” to mainstream adoption. Instead, Pinterest grew a devoted base of users – most of them female – who enjoy “pinning” items they find around the Web. While clothing, home decor and recipes dominate the site, inspirational quotes and humor are also