This excerpt taken from the PG 8-K filed Feb 10, 2009.
Most of our revenue transactions represent sales of inventory, and we recognize revenue when title, ownership and risk of loss transfer to the customer, which can be on the date of shipment or the date of receipt by the customer. The revenue recorded is presented net of sales and other taxes we collect on behalf of governmental authorities and includes shipping and handling costs, which generally are included in the list price to the customer. A provision for payment discounts and product return allowances is recorded as a reduction of sales within the same period that the revenue is recognized. We offer sales incentives to customers and consumers through various programs, consisting primarily of customer pricing allowances, merchandising funds and consumer coupons. The cost of these programs is recognized as incurred and recorded as a reduction of sales. Given the nature of our business, revenue recognition practices do not contain estimates that materially affect results of operations.