A picture’s worth a thousand words and, hopefully for marketers, a thousand shares.

Meet Pinterest, the new social network that’s drumming up a lot of interest. Mashable has an intro to Pinterest that we found pretty useful, but in a nutshell, it’s a social media site (or “online pinboard”) for posting images. The site has more than four million users now  and it’s growing quickly. Nearly six out of 10 users are women between the ages of 25 and 44. Moreover the number of visits to the site is increasing by leaps and bounds.

Besides the sharing and discussion among Pinterest members (the site is accessible by invite-only), the network has been cited as place to pick up on trends, which may be just as valuable.

For more stats on Pinterest (and other hot social networks from 2011), check this out.