Your QA environment needs 'cattle', not 'pets'
It doesn’t matter if you’ve got a team of human QA testers or you’re using one of the many automated testing solutions out there, the truth is this: if you have poor data seeding your QA strategy is going to suffer tremendously. If you do it properly, it enables you to run your whole test suite concurrently, keep your tests focused on the actual functionality they should be testing, and make maintenance easier.