In order to exploit the power of the amplifier, loudspeaker cables should have the lowest possible internal resistance for efficient power transfer. This is particularly important for speaker connections. Just think, if you have a 4-ohm speaker and a 0.5-ohm speaker cable, you could be losing at certain frequencies 11% of your amp power through the cable!
For every 100 watts your amp is believed to be given out, it may only be 89 watts! Obviously, it pays to use high current cables if you are running low impedance speakers with your amp. Unless, you can afford to burn those watts away just to heat up your cables!