definiens: shall mean the gross amount invoiced by Purchaser or its Affiliates for Product sales, less:(i ) reasonable and customary cash discounts consistent with the Seller ’s past practices, ( ii ) customary rebates and Chargebacks, consistent with the Seller ’s past practices and ( iii ) sales credits, refunds, returns and allowances accrued by Purchaser inaccordance with GAAP . Such amounts shall be determined from books and records maintained by Purchaser in accordancewith GAAP, consistently applied . To the extent that any accrual contemplated by the foregoing clause ( iii ) is subsequentlyadjusted in accordance with GAAP, Purchaser shall notify Seller thereof in writing and the Earnout owing hereunder in respectof the Product Net Sales corresponding to such accrued amounts shall be adjusted accordingly and the next subsequentEarnout payment hereunder shall be increased or decreased accordingly