What's the deal with "oxygen free" copper cable?

There's lots of buzz in the high end audio community about premium speaker cables. Some sell for hundreds of dollars for a set only a few feet long.

While "oxygen-free" cable may be of slightly higher quality, it is all but impossible to prove that there is any increase in audio quality from using this type of wire. The presence of small trace elements of iron and other minerals has no discernable impact on the performance of the cable. At best, you might increase conductivity by a measley 1% at room temperature.

The best place to spend your money is on buying speaker cables of the proper gauge and making sure that they have jackets that allow them to be durable, yet still easy to coil.

Here's what wikipedia has to say about "oxygen free" copper cable.