of receipt by the customer is not readily available. In these cases, we estimate the date of receipt by the customer based upon historical delivery times by geographic location. On the basis of our tests of actual transactions, we have no indication that these estimates have been materially inaccurate historically.

As part of our revenue recognition policy, we record estimated sales returns and miscellaneous claims from customers as reductions to revenues at the time revenues are recorded. We base our estimates on historical rates of product returns and claims, and specific identification of outstanding claims and outstanding returns not yet received from customers. Actual returns and claims in any future period are inherently uncertain and thus may differ from our estimates. If actual or expected future returns and claims were significantly greater or lower than the reserves we had established, we would record a reduction or increase to net revenues in the period in which we made such determination.

Allowance for Uncollectible Accounts Receivable

We make ongoing estimates relating to the ability to collect our accounts receivable and maintain an allowance for estimated losses resulting from the inability of our customers to make required payments. In determining the amount of the allowance, we consider our historical level of credit losses and make judgments about the creditworthiness of significant customers based on ongoing credit evaluations. Since we cannot predict future changes in the financial stability of our customers, actual future losses from uncollectible accounts may differ from our estimates. If the financial condition of our customers were to deteriorate, resulting in their inability to make payments, a larger allowance might be required. In the event we determine that a smaller or larger allowance is appropriate, we would record a credit or a charge to selling and administrative expense in the period in which such a determination is made.

Inventory Reserves

We also make ongoing estimates relating to the net realizable value of inventories, based upon our assumptions about future demand and market conditions. If we estimate that the net realizable value of our inventory is less than the cost of the inventory recorded on our books, we record a reserve equal to the difference between the cost of the inventory and the estimated net realizable value. This reserve is recorded as a charge to cost of sales. If changes in market conditions result in reductions in the estimated net realizable value of our inventory below our previous estimate, we would increase our reserve in the period in which we made such a determination and record a charge to cost of sales.

Contingent Payments under Endorsement Contracts

A significant portion of our demand creation expense relates to payments under endorsement contracts. In general, endorsement payments are expensed uniformly over the term of the contract. However, certain contract elements may be accounted for differently, based upon the facts and circumstances of each individual contract.

Some of the contracts provide for contingent payments to endorsers based upon specific achievements