[pushkins]

Walmart are known to buy not just in paint, but other products as well, below quality control products. These would be products that may not meet the quality control standards of a brand so the manufacturer sells them to other outlets under a different label and at reduced proices.
Because of this buying pattern the quality cannot be guaranteed from batch to batch to be the same. The paint may do the same job but it's longevity and application will not be the same.
Generally speaking paint that "splatters" easy and forms runs has a far more waterery consistancy. Water is cheaper than the bonding agents that helps paint stick and bond better to surfaces.