Pinterest has had an impressive year so far in terms of growth. In April, it overtook Tumblr and LinkedIn as the third most popular social network in the U.S. — directly behind social giants like Facebook and Twitter.

The bookmarking site’s success doesn’t lie solely in its user base; it’s also a powerful source of referral traffic, especially among e-commerce sites. A new study found that buyers referred from Pinterest are 10 percent more likely to make a purchase than those sent from other social networks.

Shopify — a web-based e-commerce platform — analyzed data from 25,000 of its online stores and found that Pinterest now delivers as much traffic to retailers as Twitter. At 3.6 percent, Pinterest is sending more referral traffic to stores than Google+, YouTube, and LinkedIn combined.

It seems that clothing retailers are seeing the most benefit from Pinterest. Apparel referral traffic rose 289 percent from July to December 2011. Additionally, pins with prices get 36 percent more likes than those without.

More information about Pinterest’s influence on Shopify’s stores specifically can be found in the infographic below. As with most social networks, popularity wanes, but Pinterest seems to be holding a captive audience as brands continue to connect with their target markets. It’s worth taking the platform for a test drive to see how it will benefit your brand.

[Via: AllTwitter, Image credit: Andres Rueda]