PS Audio M700 why would I biwire?

I'm getting the M700s today and noticed two sets of binding posts on the back.  I was told one is for biwiring.  But why would I want to do that?  it's still one amp.  You're just adding in extra speaker cable for apparently no reason.  Or are you bypassing some crossover circuitry which, in theory, is a more direct signal path?

Is there really a benefit to this?