Animation showing the openings of walmarts across the country by year:
mapped the spread of Walmart using Modest Maps. It starts slow and then spreads like wildfire in the southeast and makes its way towards the west coast.
...or like malignant melanoma.
However, I should state that I've gotten over my hatred of Walmart (but I still haven't been in one in years), once I came to the realization that they are merely the end result of the current rules of the game of commerce that we have established. Like Marlo Stanfield, Walmart is merely the evolutionary sociopath as produced by a form of Darwinism in, in this case, trade/commerce/business that rewards the fiercest, most inhuman creature within the system.
...and if that's the case, it is time to change the rules.