What is the name of the customer who purchased the product with the highest net profiit?
highest net profit = Max(Subtract (Unit Price, Unit Cost)); name of customer refers to Customer Names
SELECT `Customer Names` FROM ( SELECT T1.`Customer Names`, T2.`Unit Price` - T2.`Unit Cost` AS "net profit" FROM Customers T1 INNER JOIN `Sales Orders` T2 ON T2._CustomerID = T1.CustomerID ) ORDER BY `net profit` DESC LIMIT 1