No kidding! I mean when you're spinning bar type traction tires or tractor tires you'd think it would be tractive overkill, but apparently chains perform beyond even the most aggressive rubber.
I've read, though, that skidders and heavy equipment are sometimes wrapped with "tire protection chains" primarily to extend the life of the tire. I take it improved traction is a peripheral benefit with this type of chain.

Here's a typical protection chain:



Here's an offroad traction chain ( <img src="/forums/images/graemlins/mrt.gif" alt="" />Pretty, no? <img src="/forums/images/graemlins/mrt.gif" alt="" />)