Service virtualization is like using a wind tunnel to test your software. A new model of an aircraft before going to mass market production will be tested in a wind tunnel in different conditions. You can test software in a wind tunnel as well, by using Traffic Parrot.
Are your testers and developers often blocked by other teams? Do you find at least 5 bugs in production per release, and you would like to instead find them in earlier stages of SDLC to reduce costs? Is one of the systems you depend on available only 2 days a week and you need it 5 days a week for testing your application? Is setting up test data in external systems expensive or time-consuming? Are you paying high third party system transaction fees every time you run the same suite of tests? Are you waiting for an external team to deliver an API you need for functional testing of your system?
Traffic Parrot helps with these problems by simulating backend and third party dependencies. For example, a tester will use Traffic Parrot to create virtual services to simulate a backend server. That will allow her to continue testing even if the backend server is unavailable. It also helps with setting up the test data; it is much easier to do that in a virtual service she has control over. You can manually craft the virtual service based on request/response pairs or create them by doing a recording of the traffic between your application and the backend or third party system.