I am not sure if you have come across Simons Cat. It is a brilliant example of viral marketing and a very good example of a successful online presence.
Yes, I guess you need to appreciate cats but the concept and animation is simply superb.
Its also absolutely great fun even if you don't like cats - the website gets 60,000 hits a day too.
What's great, of course, is the viral nature of the marketing. Whilst Coca Cola could afford to spend millions on a marketing campaign, here they can create one for a fraction of that, and let it self-target to their core audience.
I doubt this will persuade many people to try their products for the first time, but it helps reinforce their brand image, and tries to prevent people regarding them as a major corporate, but rather as an organisation that 'gets the joke' and is 'one of us'.