For the delivery of the new RwandAir fleet, I get the opportunity to work on an interesting event marketing project. I can tell you right now the results are instant and easily traceable.
Well, it took a couple of brainies, lots of coffee, and Internet connectivity to come up with that. Facebook's Social Graph API allows you to get the most out of the millions of interconnected Facebookers across the globe when passing a message out. Without breaching into users privacy like email marketing still struggles to avoid, or pushing bulk emails to users whom you are 75% sure will click the "unsuscribe" link, Facebook places your message into a social context and leaves the society to handle the rest. On both sides you get customers from corners you never imagined, and your new customers enjoy a service that was either recommended to them or fetched from a trusted source (Facebook friends)... This is called targeted marketing!
All you need to do is plug an add-on into the service/product you'd like to put under the spotlight and log to Facebook Developers page to analyze the progress. The Facebook social fabric grows exponentially, so will your customers database! In the end, it matters less if you manage to translate your new customers into clients than staying in touch and turning your "relationship" into a buying promise.
Marketing has always been about the people, not about the product.