Weighing the financial considerations of owning and operating a data center facility versus employing a cloud infrastructure requires detailed and careful analysis. In practice, it is not as simple as just measuring potential hardware expense alongside utility pricing for compute and storage resources. The Total Cost of Ownership (TCO) is often the financial metric used to estimate and compare direct and indirect costs of a product or a service. Given the large differences between the two models, it is challenging to perform accurate apples-to-apples cost comparisons between on-premises data centers and cloud infrastructure that is offered as a service. In this presentation, we explain the economic benefits of deploying a web application in the Amazon Web Services (AWS) cloud over deploying an equivalent web application hosted in an on-premises data center and highlight the 5 things to not forget while calculating TCO.