The ability to create tests that include thousands of simulated users and can be run from any web browser. For example, I have used this software to test eCommerce platforms to ensure they are able to handle peak loads and traffic spikes. One limitation of this software is that it does not support integration with other products such as Selenium and TestComplete which make it difficult to compare results between different tools. It's also hard to get people who understand how to use this product, so training and support costs are high. Load stress testing has become more important to businesses as data shows that customers are switching sites in the face of overloads or poor performance. We use this software to measure the performance of our eCommerce platform under peak loads and we've never had a problem.