Earlier this year, Pinterest surpassed Twitter as a source of referral traffic to websites. The year of the Pin continues, as Pinterest pushes even further ahead of the microblogging platform.

A study performed by the content-sharing tool Shareaholic — which has been tracking Pinterest throughout the year — revealed that the company is now beating out Twitter, StumbleUpon, Bing, and Google in referral traffic.

Shareaholic defines referral traffic as referrals that don’t come through organic search or AdWords, but on other Google properties — not including Google+.

The new data shows a climb in referral traffic from .85 percent in January to 1.19 percent in June. While that doesn’t hold a flame to Google’s organic search (46.8 percent in June), it does top the search giant’s referral traffic (1.09 percent).

Twitter also saw some growth, but not enough to overtake Pinterest. The microblogging site climbed from .82 percent in February to .92 percent in June.

However, to be fair, it seems that Pinterest’s impressive numbers wavered slightly between March and May. According to Shareaholic’s data, the site came in last during those months. It’s unclear what caused the recent spike, but it’ll be interesting to see if Pinterest can keep hold.

Despite fluctuations, Shareaholic suggests using Pinterest as an additional form of SEO (not a replacement). If you have the extra bandwidth and a clear strategy in mind, it’s time to start pinning.

[Via: AllTwitter, Image credit: midiman]