17 Non-GAAP Definitions Adjusted EBITDA is defined as operating income plus: (1) stock-based compensation expense, including compensation expense related to certain subsidiary equity plans; (2) acquisition-related impacts, including (i) amortization of intangible assets and goodwill and intangible asset impairment, (ii) gains (losses) recognized on changes in the value of contingent consideration arrangements; and (iii) upfront consideration paid to settle employee compensation plans of the acquiree; (3) certain infrequently occurring items, including restructuring; (4) items included in Legal reserves, occupancy tax and other, which includes reserves for potential settlement of issues related to transactional taxes (e.g. hotel and excise taxes), related to court decisions and final settlements, and charges incurred, if any, for monies that may be required to be paid in advance of litigation in certain transactional tax proceedings; (5) gains (losses) realized on revenue hedging activities that are included in other, net; and (6) depreciation. The above items are excluded from our Adjusted EBITDA measure because these items are noncash in nature, or because the amount and timing of these items is unpredictable, not driven by core operating results and renders comparisons with prior periods and competitors less meaningful. We believe Adjusted EBITDA is a useful measure for analysts and investors to evaluate our future on- going performance as this measure allows a more meaningful comparison of our performance and projected cash earnings with our historical results from prior periods and to the results of our competitors. Moreover, our management uses this measure internally to evaluate the performance of our business as a whole and our individual business segments. In addition, we believe that by excluding certain items, such as stock-based compensation and acquisition-related impacts, Adjusted EBITDA corresponds more closely to the cash operating income generated from our business and allows investors to gain an understanding of the factors and trends affecting the ongoing cash earnings capabilities of our business, from which capital investments are made and debt is serviced. | 
