The microblogging service has surged ahead in recent months, being linked to 9,506 email campaigns in June compared to 8,636 for Facebook.
"In the data Email Data Source has been tracking, there has been a dramatic increase in the number of email marketing campaigns that contain links to Facebook and Twitter," said Bill McCloskey, the company's chairman and co-founder, in a statement. "In fact, starting in 2009 Twitter.com and Facebook.com have become the two most prominent linked to sites in all of email marketing."
Two years ago, only 215 campaigns that linked to Twitter. Last year, that figure grew 10-fold to 2,540 while email links to Facebook jumped to 12,650 from 729 the year before. --Mark Walsh