Our earnings release contains some or all of the following financial measures that have not been calculated in accordance with United States Generally Accepted Accounting Principles ("GAAP"): (i) non-GAAP gross profit and gross margin, (ii) non-GAAP operating income and operating margin, (iii) non-GAAP net income, and (iv) non-GAAP diluted earnings per share. As set forth in the "Unaudited Reconciliation of Non-GAAP Financial Measures" table found above, we derive such non-GAAP financial measures by excluding certain expenses and other items from the respective GAAP financial measure that is most directly comparable to each non-GAAP financial measure. Management uses these non-GAAP financial measures to evaluate our operating performance and compare it against past periods, make operating decisions, forecast for future periods, compare our operating performance against peer companies and determine payments under certain compensation programs. These non-GAAP financial measures provide management with additional means to understand and evaluate the operating results and trends in our ongoing business by eliminating certain non-recurring expenses (which may not occur in each period presented) and other items that management believes might otherwise make comparisons of our ongoing business with prior periods and competitors more difficult, obscure trends in ongoing operations or reduce management's ability to make useful forecasts.

We provide investors with non-GAAP gross profit and gross margin, non-GAAP operating income and operating margin, non-GAAP net income and non-GAAP diluted earnings per share because we believe it is important for investors to be able to closely monitor and understand changes in our ability to generate income from ongoing business operations. We believe these non-GAAP financial measures give investors an additional method to evaluate historical operating performance and identify trends, an additional means of evaluating period-over-period operating performance and a method to facilitate certain comparisons of our operating results to those of our peer companies. We also believe that providing non-GAAP operating income and operating margin allows investors to assess the extent to which our ongoing operations impact our overall financial performance. We further believe that providing non-GAAP net income and non-GAAP diluted earnings per share allows investors to assess the overall financial performance of our ongoing operations by eliminating the impact of share-based compensation expense, acquisition-related expenses, restructuring-related charges, litigation settlement gains, losses and expenses, certain deferred executive compensation and certain tax items which may not occur in each period presented and which may represent non-cash items unrelated to our ongoing operations. We believe that disclosing these non-GAAP financial measures contributes to enhanced financial reporting transparency and provides investors with added clarity about complex financial performance measures.

We calculate non-GAAP gross profit by excluding from GAAP gross profit, share-based compensation expense and acquisition-related expenses. We calculate non-GAAP operating income by excluding from GAAP operating income, share-based compensation expense, acquisition-related expenses, restructuring-related charges, litigation settlement gains, losses and expenses and certain deferred executive compensation. We calculate non-GAAP net income and diluted earnings per share by excluding from GAAP net income and diluted earnings per share, share-based compensation expense, acquisition-related expenses, restructuring-related charges, litigation settlement gains, losses and expenses, certain deferred executive compensation and certain tax items which may not occur in all periods for which financial information is presented. We exclude the items identified above from the respective non-GAAP financial measure referenced above for the reasons set forth with respect to each such excluded item below:

Share-Based Compensation - because (1) the total amount of expense is partially outside of our control because it is based on factors such as stock price volatility and interest rates, which may be unrelated to our performance during the period in which the expense is incurred, (2) it is an expense based upon a valuation methodology premised on assumptions that vary over time, and (3) the amount of the expense can vary significantly between companies due to factors that can be outside of the control of such companies.

Acquisition-Related Expenses - including such items as, when applicable, amortization of acquired intangible assets, fair value adjustments to contingent consideration, fair value charges incurred upon the sale of acquired inventory, acquisition-related professional fees, deemed compensation expenses and interest expense on seller-financed debt, because they are not considered by management in making operating decisions and we believe that such expenses do not have a direct correlation to our future business operations and thereby including such charges does not accurately reflect the performance of our ongoing operations for the period in which such charges are incurred.

Restructuring-Related Charges - because, to the extent such charges impact a period presented, we believe that they have no direct correlation to our future business operations and including such charges does not necessarily reflect the performance of our ongoing operations for the period in which such charges are incurred.

Litigation Settlement Gains, Losses and Expenses- including gains, losses and expenses related to the resolution of other-than-ordinary-course threatened and actually filed lawsuits and other-than-ordinary-course contractual disputes, because (1) they are not considered by management in making operating decisions, (2) such gains, losses and expenses tend to be infrequent in nature, (3) such gains, losses and expenses are generally not directly controlled by management, (4) we believe such gains, losses and expenses do not necessarily reflect the performance of our ongoing operations for the period in which such charges are recognized and (5) the amount of such gains or losses and expenses can vary significantly between companies and make comparisons less reliable.