my guess would be that they move an absolutely tiny amount of air, and pressure is force * area. They explained that since air is a very poor conductor of heat,

my guess would be that they move an absolutely tiny amount of air, and pressure is force * area. They explained that since air is a very poor conductor of heat, most of the heat tends to pile up in a thin boundary layer next to the fins, and just exhausting that will get you most of the cooling performance.