software upgrade rights or the non-software services, revenue is allocated to these rights and services based on the Company’s ESPs. Amounts allocated to the unspecified software upgrade rights and non-software services are deferred and recognized on a straight-line basis over the estimated lives of each of these devices, which range from 24 to 48 months. The Company’s process for determining ESPs involves management’s judgment. The Company’s process considers multiple factors that may vary over time depending upon the unique facts and circumstances related to each deliverable. If the facts and circumstances underlying the factors considered change, including the estimated or actual costs incurred to provide non-software services or the estimated lives of the related devices, or should future facts and circumstances lead the Company to consider additional factors, the Company’s ESP for software upgrades and non- software services related to future sales of these devices could change. If the estimated life of one or more of the devices should change, the future rate of amortization of the revenue allocated to the software upgrade rights would also change. 

The Company records reductions to revenue for estimated commitments related to price protection and for customer incentive programs, including reseller and end-user rebates, and other sales programs and volume-based incentives. For transactions involving price protection, the Company recognizes revenue net of the estimated amount to be refunded, provided the refund amount can be reasonably and reliably estimated and the other conditions for revenue recognition have been met. The Company’s policy requires that, if refunds cannot be reliably estimated, revenue is not recognized until reliable estimates can be made or the price protection lapses. For customer incentive programs, the estimated cost of these programs is recognized at the later of the date at which the Company has sold the product or the date at which the program is offered. The Company also records reductions to revenue for expected future product returns based on the Company’s historical experience. Future market conditions and product transitions may require the Company to increase customer incentive programs and incur incremental price protection obligations that could result in additional reductions to revenue at the time such programs are offered. Additionally, certain customer incentive programs require management to estimate the number of customers who will actually redeem the incentive. Management’s estimates are based on historical experience and the specific terms and conditions of particular incentive programs. If a greater than estimated proportion of customers redeem such incentives, the Company would be required to record additional reductions to revenue, which would have a negative impact on the Company’s results of operations. 

Valuation and Impairment of Marketable Securities 

The Company’s investments in available-for-sale securities are reported at fair value. Unrealized gains and losses related to changes in the fair value of securities are recognized in accumulated other comprehensive income, net of tax,