The rise of the internet along with the perceived reduced effectiveness of television and other mass media advertising has spurred the growth of stunt marketing: using your product or brand to ambush unsuspecting consumers and making them a participant in your demonstration or event.
The best examples of this are well planned, produced and promoted. It's not enough to create the event. You must capture the event then spread the video obtained from the stunt on Youtube and Vimeo for all to see, because unlike a television spot, you can't run event after event until millions of people participate.
Like all marketing, when you decide to produce a brand stunt the key questions to ask are: Is it relevant to our target? Does it fit our brand? How will it help us sell more product?
Don't let views, shares, tweets and likes be the only metrics by which you judge your event. If you can't link it to actually moving the needle in things like awareness, preference, trial or sales, there are probably better places to invest your marketing dollar, no matter how much fun your event is to stage.