The road to marketing greatness is paved with failed marketing campaigns. There are big name brands that have failed tremendously in their attempts to build brand awareness, direct market, and sell their new products.
The aim of a viral marketing campaign, whether it’s online or offline, is to spread as much and effective as possible, by offering a story that is worth sharing.
With the lower cost of producing a viral video or using online media, creating content that spreads isn’t such an issue (although you should not give the content, such as online video, less attention “because it’s online”, great video content and other creative content and stories have their price).
However, the main issue is the simplicity and the tip-ability of the content.
You need to create something that can reach a tipping point, and spread without requiring explanation.
Appeal to a subgroup, by all means, but make sure your message can spread outside that subgroup and into the mainstream.