It is impossible to create viral content. If anyone sets out to create something for the specific purpose of going "viral" then the content will be forced, fake and forgotten. Focus, instead, on creating something that serves the audience.
A Che Guevara portrait isn't necessarily going to be successful because of it's subject matter. The photograph actually needs to be greater than the competition, just like Christ's majesty doesn't mean every crucifixion is going to be great art.