This is an elaboration of the expression "word of mouth" in which something (usually a product or service) is spoken about either favourably or in a good light. This phrase has been introduced to reflect the impact of social media which now allows these comments to go viral, and quite simply become world of mouth rather than word of mouth.
The latest Harry Potter film has received good reviews through world of mouth marketing!
by world of mouth me July 08, 2011
Can you define these popular missing words?