The process of evaluating the potential impairment of goodwill is subjective and requires significant judgment. In estimating the fair value of the reporting units, we make estimates and judgments about the future cash flows of the reporting unit. These estimates include assumptions about future market growth and trends, fore- casted revenue and costs, capital investments, appropriate discount rates, and other variables that can significantly affect the value of the reporting unit. 

Although our cash flow forecasts are based on assumptions that are consistent with plans and estimates we use to manage the underlying business, there is significant judgment in determining the cash flows attributable to these businesses over a long-term horizon. We update these assumptions and cash flow estimates at least annually. 

We believe that the accounting estimate related to goodwill impair- ment is a critical accounting estimate because the assumptions used are highly susceptible to changes in the operating results and cash flows of the reporting units included in our segments. If actual results differ from our estimates, future tests may indicate an impair- ment of goodwill. This would result in a non-cash charge, adversely affecting our results of operations. 

## Impairment of Long-Lived Assets 

Our Consolidated Balance Sheet as of December 31, 2010 includes $62.1 million of property, equipment, and capitalized software, net of accumulated depreciation, and $169.0 million of intangible assets, net of accumulated amortization. In accordance with FASB ASC 360-10-35, Subsequent Measurement—Impairment or Disposal of Long-Lived Assets , we review our property, equipment, capitalized software, and intangible assets for impairment whenever events or changes in circumstances indicate that the carrying value may not be recoverable. Such events or changes may include deteriora- tion in the business climate for a specific product or service. If the total of projected future undiscounted cash flows is less than the carrying amount of an asset, we may need to record an impairment loss based on the excess of the carrying amount over the fair value of the assets. 

Estimates of future cash flows and the estimated useful lives asso- ciated with these assets are critical to the assessment of recover- ability and fair values. They are susceptible to change from period to period because of the requirement to make assumptions about 

future cash flows generated over extended periods of time. Changes in these estimates could result in a determination of asset impair- ment, which would result in a reduction to the carrying value and could adversely affect our operating results in the related period. 

## Stock-Based Compensation 

We include stock-based compensation expense in each of our oper- ating expense categories. Our stock-based compensation expense primarily reflects grants of restricted stock units and restricted stock. 

Under FASB ASC 718, Compensation—Stock Compensation , stock- based compensation expense is measured at the grant date based on the fair value of the award, and the cost is recognized as expense ratably over the award’s vesting period. We measure the fair value of our restricted stock units on the date of grant based on the mar- ket price of the underlying common stock as of the close of trading on the day prior to grant. We estimate expected forfeitures of stock- based awards at the grant date and recognize compensation cost only for those awards expected to vest. We ultimately adjust this forfeiture assumption to the actual forfeiture rate. Therefore, changes in the forfeiture assumptions do not impact the total amount of expense ultimately recognized over the vesting period. Instead, different forfeiture assumptions would only impact the timing of expense recognition over the vesting period. 

Because our largest annual equity grants typically have vesting dates in the second quarter of the year, we adjust the stock-based compensation expense at that time to reflect those awards that ultimately vested. In addition, we update our estimate of the for- feiture rate that will be applied to awards not yet vested. In 2010 and 2009, we recorded approximately $0.2 million of additional stock-based compensation expense related to these changes in estimates. 

We believe that the estimates related to stock-based compensation expense are critical accounting estimates because the assumptions used could significantly impact the timing and amount of stock- based compensation expense recorded in our Consolidated Financial Statements. 

