A piece of content will rarely go viral if it doesn’t encourage its audience to engage. Viral marketing works best when it’s designed for the audience to interact and easily share.
At the very least, your content needs to include some sort of call to action (CTA), telling users what action they should take after hearing your message. Some of the most successful viral marketing campaigns also include opportunities for the audience to comment, create their own content, or otherwise play along.
Your goal is to ensure your viewers don’t take their eyes off the screen until they’ve shared your content with their own networks. If your campaign can engage media outlets as well, that’s all the better to help you gain publicity.