What is the company's profit on the product that was rated second-highest by David?
profit on net on a single product = SUBTRACT(ListPrice, StandardCost); second highest rating refers to Rating = 4; David is the ReviewerName;
SELECT T2.ListPrice - T2.StandardCost FROM ProductReview AS T1 INNER JOIN Product AS T2 ON T1.ProductID = T2.ProductID WHERE T1.ReviewerName = 'David' ORDER BY T1.Rating DESC LIMIT 1