The SAT Subject Tests are a perfect way to help differentiate yourself. Differentiate means to recognize what makes someone or something different. Companies focus on differentiating their products from other products so that they'll stand out as a good purchase. They do this because they're competing with other companies who have similar products. You need to consider the college admission process as a similar type of competition. You're competing against other students. Anything that helps you differentiate yourself from those students is something worth your time and effort.