Word of mouth marketing emerges as the dominant new
marketing technique, according to a survey done by CMO

When the survey asked marketers “which of the following
emerging marketing techniques are you currently using or
planning to use within the next six months,” 69.85 percent
said “customer influence via word of mouth.” That was
second only to “email marketing” with 69.85 percent
(respondents could check multiple techniques).

Word of mouth looks even more pervasive when other word of
mouth-related responses are added in. Blogs were cited by
22.45 percent, “stealth marketing” by 14.55 percent, and
“determined detractors” by 2.91 percent

More info: http://www.cmomagazine.com/survey/CMO_Reality_Check_Poll.pdf