How do I include platform fees, shipping costs, and return costs in the SKU gross margin table?

Many e-commerce teams only look at SKU gross margin by subtracting the purchase price from the selling price, and as a result, they find themselves working harder the more their best-sellers sell. We previously had an SKU that looked like it had a decent gross margin, but after factoring in platform fees, last-mile shipping, and returns, its actual contribution was very low. My approach is to…