why performance testing

Performance testing is mainly conducted to address various problems/risks that are close to expense, cost and company’s reputation. Performance testing gives us a chance to estimate the performance of the application under test. To avoid the chances of end users not willing to use the application because of its slow response times, which may lead to high revenue loss, loss of reputation, loss of existing and new customers for the company which own the application? So, performance testing gives us a chance to find out the application health in terms of its behavior for high loads/ different load levels / peak loads etc.. Also we can find out the how the application runs if the load increases in future because of newly added customers. So forecasting can be done easily using performance testing. I.e how much load the current infrastructure can handle? If the load increases in future, whether the current infrastructure can handle it? So, depending upon these statistics the company can set up the infrastructure that is needed.