What is the appeal of John Piper (Desiring God Ministries)?

This question is not a slight or belittlement of the pastor but I simply don't understand. He is the most referenced and watched pastor at my college, even among those that wouldn't identify as Calvinists. His doctrine and demeanour doesn't resonate with me personally, but that's unimportant. My confusion stems from the fact that, out of all the Reformed theologians and apologists in America, what about him specifically?