Net Margin Value is obtained by subtracting all the fees and expenses from the Gross Merchandise Value. More realistic look into how business is actually performing as it takes into account costs, refunds, etc. [1] [2]
[1] Gross Merchandise Value (GMV): Definition, Formula, Examples | Yieldify. Retrieved May 21, 2021, from https://www.yieldify.com/blog/gross-merchandise-value-gmv/
[2] Corporate Finance Institute. Retrieved May 21, 2021, from https://corporatefinanceinstitute.com/resources/knowledge/accounting/profit-margin/