A very interesting study stumbled upon while reading the NYU PR graduate school blog
Surprisingly, the study found that less than 40% of consumers use e-mail to make recommendations to others, including via personal e-mail (37%), by e-mail forwarding (32%) or through mass e-mails (12%). While slightly higher percentages of Influentials use e-mail (personal e-mail 53%, e-mail forwarding 39% and mass e-mails 18%), face-to-face communication still far outweighs this medium.