As the images streamed out of Charlottesville, Va., this month showing white nationalists protesting the removal of a statue of Robert E. Lee, many could not help noticing the product illuminating the faces twisted into sneers of hate: Tiki torches.

Melanie Lichtfeld, owner of a Madison, Wis.-based plumbing company, used to tell customers they could wait weeks to buy their new kitchen sink from a local supplier. Now she orders the parts she needs on Amazon.com and they arrive two days later.