A new study from content-sharing firm Shareaholic has revealed that the social sharing platform Pinterest, which was established less than two years ago, is now the fastest-growing site for referral traffic.

In January, Pinterest drove only a fraction less referral traffic than both Twitter and Google, and more than Google+, YouTube and LinkedIn combined.

Shareaholic tracked data from 200,000 publishers that reach more than 260 million monthly unique visitors, and have summarized their results in this table, which shows referral traffic for December 2011 and last month.

Key takeaways:

• Total referral traffic from Pinterest rose from 2.5 percent in December to 3.6 percent in January – back in July last year Pinterest accounted for just 0.17 percent of referrals, so this is impressive growth
• Twitter has been consistent month-to-month, accounting for 3.62 percent and 3.61 percent of all referrals respectively
• Facebook dominates all referral traffic, accounting for 26.4 percent in January, which was up on the previous month, ahead of second-placed Stumbleupon, which dipped

(Source: Shareaholic.)