Like an epidemic, a clever viral advert is passed on from one user to another and so on and so forth. The advert/product is distributed exponentially to an ever-increasing mass audience.

A most notable and unfortunate example of this viral effect happened over two centuries ago with a wave of suicides that swept across Europe – just like an infectious disease.

Interestingly though, the catalyst is strongly suspected to be German author Johann Van Goethe's “The Sorrows of Young Werther”; a tragic tale in which unlucky in love hero Werther commits suicide; the resultant actual suicides had many similarities to Werther's. The thesis is known as social contagion and suggests that opinion and belief can spread like the plague; almost inhibiting the recipients choice on the matter.

This is the potential goldmine that we as marketers sit on; now remove the romantic novel and introduce the internet…

More recently and possibly easier for us to relate to is the “star wars kid” – a short video clip of a student pretending to be a Jedi knight; which has to date had nearly 900 million views – if ever there was need for validation that Google's $1.6bn spurge on YouTube was no waste of money.

Now the problem is that viral marketing is hard to track, and thus hard to determine what works and what doesn't. Even 900m views doesn't necessarily mean a huge boost in sales; it would have been nice if the video maker were selling something.

A commercial example is John Wests Salmon advert – the one where the fisherman fights the bear – You would buy the salmon in the supermarket so there is yet again no way of directly relating any increase in sales back to this hugely popular viral video.

It won't be too long before technology saves the day here, but for the meantime it's still a bit hit or miss. Of course it will be neither if you don't go out nor try for yourself.

Article marketing is probably the easiest and most accessible way of producing something with viral potential so why not start there. The idea is to write a good quality article on your chosen niche and submit to article directories.

Dependant on quality, your article may be picked up by website and/or newsletter owners who will distribute the article for you.

Within the copyright clause you can include a link back to your website and hey presto – your first viral campaign; not to mention you'll be building backlinks.

If you feel more creative then why not have a look into producing mini video clips for posting on YouTube and Myspace; accrediting a website URL in the title sequence and end credits.

“They” say it's “The future of entertainment”. Make no mistake viral marketing is very much the future of advertising too; learn as much about it as you can.