Well, you long enough and you find something that makes sense... I found a company that makes textured/dimpled vinyl wraps for cars, and their explanation is as such:
"Each dimple causes micro air turbulence (3mm thick product), and this creates a continuous air "pillow" across the entire surface of the car. The result is that the friction is no longer between air and surface, but between air and air. This is also what allows it to seemingly stick to the shape rather than detach from the shape."
I know this concept to be true, because it is used with boats. They inject air under the hull in special pockets, and the friction between water and air is less than it would be if it were water on hull. Similar concept to hover craft which maintains zero hull on water friction. So that's an awesome explanation of how it works, or at least it is in my mind haha And it's from Germany, so the have to know what they are talking about
Companies site:
Effect | ZDRAX Supreme Surface Technologies
EDIT: Of course this would be evidence that different size dimples, and different applications of dimples, do different things (assuming they are correct with their research).
~C