Your scene lights need to be set to raytrace first of all, not shadowmap. The raytrace shader node also needs to be set to any color other than black, and have a value higher than 0. I usually use 30-50% for most surfaces, and maybe up to 60% for something very reflective like window glass. It's also good to set the reflective color to a non-white value, like a very pale gray for instance as most surfaces are not perfect reflectors.

A bit of a warning though, lots of reflective surfaces can bog down your system unless its fairly high end.