A simple and excellent website for checking train schedules

At first glance, ZuoChe.com? A bus route inquiry service? Don't plenty of websites already offer that, especially the map services websites which basically all include bus route inquiries? I looked again, and still didn't see anything particularly excellent. But then, all of a sudden I noticed that this website's Alexa ranking was at 61,501. The automobile community site I used to work for wasn't ranked as high as this, so how does ZuoChe.com attract its users? Confused, I further checked out this seemingly insignificant little website, and what happened next really made me admire them: currently, ZuoChe.com only provides bus inquiry services for four cities in China. Just four...