In photography why bother following the rules to be really creative? Why not just throw away the rule book and create beautiful images?
However, breaking up is just so hard to do, and the Rule of Thirds is just so useful that you will never want to dispose of it. It is the first composition rule that most photographers learn, and the one they will use forever.
The Rule of Thirds has been used for centuries. By Leonardo da Vinci for example.
Once you aware of the rule you will notice it countless times each day in photography, film and TV. Rarely does the subject of a photograph happily sit slap bang in the centre. Instead, it is usually more pleasing to place it one third in from the left or the right. Similarly with a horizon. In the centre would just split the image in two, a third from the top or bottom makes the image far more interesting.
Why does it work? It just does. The Rule of Thirds is one of the rules of nature.
Rachel across at Photography Talk has created a great guide on how to make it work in your photography. Check it out.