We believe that the presentation of non-GAAP net income and non-GAAP earnings per diluted share provides important supplemental information regarding non-cash expenses and significant recurring and non-recurring items that we believe are important to understanding financial and business trends relating to our financial condition and results of operations. Non-GAAP net income and non-GAAP earnings per diluted share are among the primary indicators used by management as a basis for planning and forecasting future periods and by management and our Board of Directors to determine whether our operating performance has met specified targets and thresholds. Management uses non-GAAP net income and non-GAAP earnings per diluted share when evaluating operating performance because it believes the exclusion of the items described below, for which the amounts and/or timing may vary significantly depending on the Company's activities and other factors, facilitates comparability of the Company's operating performance from period to period. We have chosen to provide this information to investors so they can analyze our operating results in the same way that management does and use this information in their assessment of our business and the valuation of our Company.
Use and Economic Substance of Non-GAAP Financial Measures
We compute non-GAAP net income and non-GAAP earnings per diluted share by adjusting GAAP net income and GAAP earnings per diluted share to remove the impact of recurring amortization of acquisition-related intangibles and stock-based compensation expense, as well as restructuring related and non-recurring charges and gains and the tax effect of these adjustments. Such non-recurring charges and gains include acquisition-related transaction expenses and the costs to integrate such acquisitions into our business, changes in the fair value of contingent consideration, corporate headquarters relocation expenses, and imputed interest expense and depreciation, net of accrued sublease income, related to the sale of our corporate headquarters facility and related land.