Back in December 2011, I wrote a post that asked 15 “power users” their thoughts about the emerging platform. At the time, Pinterest was still really a “niche” social network. Since then, Pinterest has completely blown up on it’s way to becoming THE “it” social network of 2012. Shel Holtz recently confirmed there are now more than 50 million blog posts referencing or featuring Pinterest. Wow!

And, the growth isn’t all hype either. Pinterest is driving some serious traffic for some major brands. Consider that Pinterest is now driving more traffic than Google+, LinkedIn and MySpace COMBINED and you start to get a sense this might be just the beginning.

With all this hype, usually comes questions. From your peers. From your boss. From your boss’ boss. So, it helps to have some Pinterest stats at the ready to share at the tip of a hat. Below, you’ll find 18 stats to bookmark and share with your boss when they come asking about Pinterest–because, if it continues at this rate much longer, sooner or later they will come asking.

* Pinterest is retaining and engaging users as much as 2-3 times as efficiently as Twitter was at a similar time in history.

* Etsy is the top site in terms of “source domains”–Google is second followed by FlickR, Tumblr and WeHeartit.com

* Pinterest accounted for 3.6% of referral traffic, while Twitter just barely edged ahead of the newcomer, accounting for 3.61% of referral traffic. In July 2011, Pinterest accounted for just 0.17% of referral traffic, proving the site’s blockbuster growth.

* Pinterest has 10.4 million registered users

* According to AppData and Facebook, 97% of Pinterest users are women.

* American users of the social network spend an average of 1 hour and 17 minutes on the site, well ahead of Twitter (36 minutes), LinkedIn (17 minutes) and Google+ (6 minutes).

* Top corporate Pinterest boards: Real Simple (34,517 followers), HGTV (17,824 followers), Nordstrom (9,886 followers), West Elm (11,547 followers); ModCloth (11,813 followers), Whole Foods (14,217 followers), Better Homes and Gardens (15,127 followers), Kate Spade (16,371 followers), Etsy (53,784 followers),

* Estimated unique visitors to Pinterest.com increased by 429 percent from September to December 2011

* According to comScore, the average Pinterest user spend 98 minutes per month on the site, compared to 2.5 hours on Tumblr, and 7 hours on Facebook.

* Daily Pinterest users have increased by more than 145% since the beginning of 2012.

* Over 1/5 of Facebook-connected users are on Pinterest daily (which represents more than 2,000,000 members)

* Average minutes per Pinterest visitor per month in May 2011: 13.7 minutes; average minutes per Pinterest visitor per month in January 2012: 97.8 minutes

* Top areas of the country for Pinterest users: East South Central (Mississippi, Alabama, Kentucky, Tennessee) and West North Central (Minnesota, Iowa, Missouri, Nebraska, South Dakota and North Dakota)

* The biggest demographic for Pinterest: Women ages 25-34

* Only 25% of Pinterest users have earned a bachelors or higher degree and the majority live off a household income of $25-75K.

* In the UK, the majority of Pinterest users are actually male (56% male; 44% female)

* Top interests on Pinterest in the U.S.: Crafts, Gifts, Hobbies/Leisure, Interior Design, Fashion Designers/Collections

* Top interests on Pinterest in the UK: Venture Capital, Blogging Resources, Crafts, Web Stats/Analytics, SEO/Marketing