According to the makers, copper conducts heat better than any other industrial metal and this is combined with the "structure" of foam, to dissipate heat over a larger area.
The website states (in translation):
To the very hot regions inside the metal foam, the air is heated more than in the outer regions. The air expands due to the heat in the inner stronger and is pressed automatically to the outside. This creates its own micro-circulation, which dissipates the heat more efficiently. A fan as cooling is no longer necessary. Moreover, the heat is distributed on an up to 500-fold greater surface area.
Thanks to Sue P for highlighting this one. But if you think it sounds too good to be true, you would not be the only ones. Check out this debunking post on Hackaday - Behold! The Most Insane Crowdfunding Campaign Ever
Interesting reading and a good warning to think twice before reaching for your wallet, but do read the comments below that piece that attempt to debunk the debunk!