Cable Geometry Question

I notice a lot of interconnect cables use 3 wires instead of 2, with 2 of those 3 wires from ground rather than signal. What's the advantage of doing this versus a twisted pair aside from lower inductance? Does it sound better this way? Kimber, for example, does this, but I believe some of their designs use 2 for signal rather than 2 for ground. And why use 2 of the 3 wires for ground rather than signal?