If you are trying to find what zipcodes are the ones with highest volume of sales, would the following image provide you the info
OR, would this one?
Both options show the same amount of marks, which is about 40K data points
It turns out that creating polygons to draw the zipcode boundaries is a bit more intensive than creating circles. I am not exactly sure if this will matter for all of you, but its a point worth noting.
My advise for this one would be to limit “filled maps” for county/zipcode level maps in the cases where you want to highlight density but use “density maps” instead.
However, when you are looking at maps at the State/Region/Country level, this might be a moot point