definiens: means Net Sales minus Selling Expense minus the Atrix Manufacturing Cost ; [ provided, however, that in no event shall Selling Expenses during any calendar year exceed fifteen percent ( 15 % ) of Net Sales . Any Selling Expenses in excess of fifteen percent ( 15 % ) of Net Sales during any calendar year shall be the sole responsibility of Geneva and shall Dot be deducted in determining Net Profits ): ' means Gross Sales, less customary discounts, returns, promotional allowances, volume and incentive rebates, shelf stock adjustments, other similar customary adjustments or allowances actually given to such customers in the normal course of business by Geneva, taxes the legal incidence of which is on the purchaser and separately shown on Geneva 's or its Affiliates ' invoices, and transportation, insurance and postage charges, if prepaid by, Geneva or its Affiliates and billed on Geneva 's or its Affiliates ' invoices as a separate item