This website is rather simple and easy to use. That means that there isn't much to test, but having some sort of automated test coverage is giving me peace of mind that everything works as it should.
Adding automated tests to small or create-and-forget projects probably doesn't make sense. You will spend additional time writing those tests, and this will only increase the project's cost. And you will get almost nothing in return. But, if you are working on a project that will be maintained in the future and new features will be added on a regular basis, then you most certainly need to add automated tests.