According to the blender documentation:
The Object Info node gives information about the object instance. This can be useful to give some variation to a single material assigned to multiple instances, either manually controlled through the object index, based on the object location, or randomized for each instance. For example a Noise texture can give random colors or a Color ramp can give a range of colors to be randomly picked from.
But how do you actually achieve the effect mentioned in the description? When I try randomize the texture for multiple objects the value of the location, object index or random output of the object info always returns 0.