This document discusses strategies for viral marketing and word-of-mouth advertising online. It notes that viral marketing uses a broad array of online tactics like videos, social media, games and blogs to encourage sharing of brands and products between users and peers. More extreme content that elicits strong emotions like humor, sexuality and shock are often used in viral videos to drive forwarding behavior beyond just awareness. Small businesses could benefit from thoughtful, small-scale viral marketing efforts given there are over 5 million small and medium enterprises in the UK.