That's an impressive figure, given that the two-year-old site has an estimated 11.7 million active registered users compared to Twitter's more than 100 million.
The data was provided by Shareholic, whose sharing widgets are used across more than 200,000 online publishers, mostly independent bloggers. Between them, those publishers reach some 270 million unique visitors every month.
In February, the company found that a little less than half (48.81%) of all traffic came from Google, followed by Facebook (6.38%), Yahoo (1.61%), StumbleUpon (1.29%) and Bing (1.21%). Pinterest came in sixth at 1.05%, beating out Twitter at 0.82%.
In January, Shareholic found that Pinterest sent more referral traffic to publishers than Google+, YouTube and LinkedIn combined, falling into line just behind Twitter. Women’s lifestyle, home decor and cooking magazines have been among the biggest beneficiaries of Pinterest's growth. Some are seeing bigger referral numbers from the image-collecting service than from major portals like Facebook and Yahoo.