My “LinkedIn” twitter search is buzzing with this recent blog post by Tamara of Eventbrite (h/t: All Things Digital), where she compares the ROI on social sharing for their company. Social commerce is a growing phenomenon (think Groupon) but data like this helps marketers understand the true value of incorporating the social graph into their websites. A couple of interesting tidbits from the post:

• The growing increase in the effectiveness of sharing on social networking sites – Facebook, LinkedIn and Twitter

When someone shares an event with their friends through social media, this action results in real dollars. Our most recent data shows that over the past 12 weeks, one share on Facebook equals $2.52, a share on Twitter equals $0.43, a share on LinkedIn equals $0.90.

• The resilience of email

…and a share through our ”email friends” application equals $2.34

That’s not bad at all. In terms of effectiveness, they’re ranked – Facebook, email, LinkedIn and Twitter. And, here’s the methodology:

We use a custom suite of social analytics tools that we have developed entirely in-house. Our reporting lets us track and analyze not only which sharing options our users leverage, but where on our site each share action takes place. These tools also tie back into our conversion funnels, so we are able to attribute ticket purchases to the specific social distribution channel that drove them. So, for example, we can compare not just the value created by a Facebook “Like” vs. a tweet, but also the performance of shares initiated before or after a purchase.

Reminds me of a post from Dan Yoo on the LinkedIn blog, where he talked about the effectiveness of Groupon.

“You can see the initial spike in revenue in the graph below. That’s to be expected after distributing a coupon. What we found even more interesting was the “new normal” that resulted. Even after the bump from Groupon, our revenue has leveled off to almost 50% higher than before.”

Of course, Dan works at LinkedIn and was profiled in our Talent series, where we feature employees who do cool stuff outside of their day job at LinkedIn. And, if you haven’t guessed by know, by way of disclosure, I work at LinkedIn.

Are there other studies that compare sharing ROI around? Let me know in the comments section.