Here’s some news that should warm the hearts of email marketers.

“Despite reports of its demise, email is still the most popular method of sharing, and despite its meteoric rise of late, Twitter is still not a very popular sharing channel,” writes Tim Schigel, CEO of ShareThis, the online sharing network, in a blog post.

Schigel reports that 46% of all sharing is driven by email, compared with 33% by Facebook and 14% by channels like Digg, del.icio.us and LinkedIn. Twitter’s “share” of this traffic? Only 6%.

Twitter does better when it comes to the next stage—it drives 40% of the clicks that result from sharing, compared with 35% for email and other social channels, Schigel adds. But email is the champ when it comes to a deeper level of engagement.

Email drives an average of 2.95 page views, compared with 2.76 for Facebook and 1.66 for Twitter, Schigel states.

This is in line with another recent survey showing that content shared by email generates a 36.8% conversion rate (conversion meaning purchases, subscriptions and other activity), according to eMarketer.

How does Schigel account for email’s success?

“Getting an emailed link from a friend may cause you to pay more attention than the more random discovery that you get on Twitter as you consume quick opinions,” he writes.

Schigel also notes that sharing drives one third of the Web traffic driven by search. What’s that mean? That a site that gets 100,000 unique visitors a month from search is getting 33,000 from sharing.

He also reports that shared links drive “50% more page views than search.”

Our conclusion? That email is the most robust viral medium of all. But it only works when you’re getting your message to the right people, using well-targeted email marketing lists.