How are low cost items with free shipping profitable?

Can anyone explain how items are being sold for under ~$8 and have free shipping? With fees, product, packaging, and shipping costs, how are they able to make any profit? These would have to be at least $1 at wholesale prices too.

I have a product in mind but I’d be making $0 or even maybe losing $1 or 2.
Is there any other way to find shipping under $5/6? This is the lowest rates I’ve seen for inside the US