Wordof-mouth is successful only when companies make a conscientious decision to do something unexpected that makes your customers say, "Wow, that's interesting; the competition certainly doesn't do that!"
Of all of your current marketing efforts online and offline - nothing is more important than what you're doing to encourage wordof-mouth. To be successful, you have to be remembered; to be remembered, you have to give your customers something to talk about or they'll easily forget about you. Social channels has made this even easier if you provide opportunities for your customers and fans to share information about your, your product or service through tweets, discussions, facebook posts etc.
With thousands of similar companies competing for a small wedge of attention, what are you doing to stand out? Another ho-hum TV spot, a creatively tired direct mail piece, a supposedly new digital offering?