Comment by LukeShu

Sticker Mule is one of the major internet-order small-batch/on-demand custom sticker/T-shirt/swag suppliers. You may know them from "unixstickers".

Following Trump getting shot, Sticker Mule send out a marketing email to customers encouraging them to buy a T-shirt that "shows you support Trump."

This has caused many Sticker Mule customers to seek alternatives. Sticker Ninja has benefited greatly from this (they are "slammed", as TFA says). Sticker Ninja hasn't done anything political here, and that's sort of the point; they haven't while Sticker Mule has.