I have been waking up with an allergy attack every morning for the past few weeks. Because of this wonderful site, I now know a lot more about dust mites then I knew before (which was absolutely nothing.) Turns out neglecting those fan blades IS noticeable, TO ME.
After finding that article, I did some poking around and I love all of their articles about the science of cleaning! It is awesome. (I AM NOT BEING PAID TO SAY THIS, AND THERE IS NO INCENTIVE. I simply found it inspiring. They even offer cleaning classes! Worth looking into people!