One of the success stories in the human civilization is the postal network. In some form or the other, it has existed for thousands of years. Reason? It addresses one of the core necessities i.e, communication. The success of the modern postal system also attributes to its simplicity, pay as you use, relatively free basic service and a decent reliability - Four features which most of the other services lack. These four features of any application or service are the grand rules of success. So the next time you get mails, think if your service need any refactoring?