"Viral marketing is an idea that spreads--and an idea that while it is spreading actually helps market your business or cause"
Seth Godin

The key to effective viral: Create and execute an idea that's intriguing enough to get consumers to interact. 
Theresa Howard, USA TODAY

To get the most out of social media, you need to understand how it works. Just plugging stuff or posting them online, however good is not going to help. You might be the best Chef and might have a poster made claiming that but do you think that it will help? NO, of course not. You have to be able to make sure that people see your work & know what you can create. 
I will follow up more on viral marketing later, but I have posted some great books about viral marketing in the resources section which you can refer to.