This excerpt taken from the AMZN 8-K filed Feb 2, 2005.
Limitations of Consolidated Segment Operating Income
Consolidated segment operating income has certain limitations. First, because it excludes Stock-based compensation, the financial measure does not include all expenses primarily related to our workforce. We
compensate for this limitation by providing supplemental information about stock-based compensation on the face of our consolidated statements of operations and in the footnotes to our financial statements. We also provide supplemental information about outstanding stock-based awards, including their dilutive effect on shareholders, in the footnotes to our financial statements.
Second, consolidated segment operating income excludes Other Operating Expense (Income). For companies that periodically undergo restructuring events, excluding restructuring-related costs from performance measures could provide an incomplete summary of ongoing costs that would affect future cash flows. However, we compensate for this limitation by disclosing cash flow measures, including operating cash flow, that incorporate all ongoing cash obligations associated with our January 2001 restructuring event and by providing disclosure of future estimated cash flows and remaining commitments associated with this event. Since we have initiated in the second quarter of 2004 a restructuring event in Europe, we have re-evaluated our decision to exclude such charges from our consolidated segment operating income. We have determined that it continues to be appropriate since it has been over two years since our last restructuring event, and we do not anticipate another restructuring event in the next two years. There can, however, be no assurance that we will not undertake another restructuring event in the future that would affect future cash flows.