Why the fly? Well, we needed an object that was sensitive towards airstream to illustrate the genius of the new product.

Making it a living object is always a good way to make the story relatable and make the USPs of the product almost sensuous. 

When our feelings are activated, we are much more likely to remember, what we have experienced. And if it's a good feeling like amusement it causes a chain reaction, where we unconsciously link the good feeling to the brand, thus making us more inclined to buy something from that brand.