"Virals" - don't exist.
Spanking £60k of your clients' hard earned cash, to have a load of 14 year olds in Nebraska and Moscow watch it for less than 2 seconds before they realize your wry, post modern masterpiece isn't Jemma Jameson in her next to nothings, isn’t “viral” - its just conventional "push" TV style advertising with less reach.
The grubby little secret of the "viral" world, is if your content isn’t genuinely brilliant (and therefore garnering enough views itself), little can be done to artificially manufacture buzz - to believe its possible is to fundamentally misunderstand the point of the web. It is a sad fact that many viral marketing agencies “accidentally” put clients' content on the end of other popular links to get numbers up. Even when you see "viewed by more than 500,000 people", the reality is, if you're a UK company, wanting UK eyeballs, less than 2% will be genuine views.
It is incredibly hard to predict when something (an application, a picture, a piece of music, a community or a video) will infect people's heads - turn into a meme – and go “viral”. Capturing the zeitgeist and having your brand lifted on a wave of global support takes a brilliant idea, masses of trial and error and not a small amount of luck. It cannot be replicated on demand - and anyone who says it can is lying to you.
Rolling, thoughtful and useful, time sensitive content - close media monitoring and engagement - combined with a range of community development ideas, brilliant SEO, usability, a dash of conventional push advertising (and a whole lot more besides) – is what makes a great always on marketing mix - the lottery of "the viral" shouldn't be ignored completely but it isn't a substitute for a balanced plan.