Useless. Just like all standardized tests controlled by large companies like ETS. Their main purpose is to tell colleges what your grades will be like if you attend their school. I spent hundreds of dollars on an SAT course, managed to get my score up by 100 points, and still didn't get a good score. I still placed out of the classes they wanted me to take in college, and I graduated magna cum laude, so that just goes to show how inaccurate my scores were.