SIRIUS defines ARPU as the total earned subscriber revenue and net advertising revenue divided by the daily weighted average number of subscribers for the period. ARPU is calculated as follows:

SIRIUS believes average monthly churn; SAC per gross subscriber addition; customer service and billing expenses per average subscriber; free cash flow; and ARPU provide meaningful information regarding operating performance and liquidity and are used for internal management purposes; when publicly providing the business outlook; as a means to evaluate period-to-period comparisons; and to compare the company’s performance to that of its competitors. SIRIUS also believes that investors use current and projected metrics to monitor performance of the business and make investment decisions.

SIRIUS believes the exclusion of stock-based compensation expense in the calculations of SAC per gross subscriber addition and customer service and billing expenses per average subscriber is useful given the significant variation in expense that can result from changes in the fair market value of SIRIUS common stock, the effect of which is unrelated to the operational conditions that give rise to variations in the components of subscriber acquisition costs and customer service and billing expenses. Specifically, the exclusion of stock-based compensation expense in the calculation of SAC per gross subscriber addition is critical in being able to understand the economic impact of the direct costs incurred to acquire a subscriber and the effect over time as economies of scale are reached.

These non-GAAP financial measures are used in addition to and in conjunction with results presented in accordance with GAAP. These non- GAAP financial measures may be susceptible to varying calculations; may not be comparable to other similarly titled measures of other companies; and should not be considered in isolation for, or superior to measures of financial performance prepared in accordance with GAAP.

SIRIUS refers to net loss before taxes; other income (expense) – including interest and investment income, interest expense, equity in net loss of affiliate; depreciation; and stock-based compensation expense as adjusted loss from operations. Adjusted loss from operations is not a measure of financial performance under GAAP. The company believes adjusted loss from operations is a useful measure of its operating performance. The company uses adjusted loss from operations for budgetary and planning purposes; to assess the relative profitability and on-going performance of consolidated operations; to compare performance from period to period; and to compare performance to that of its competitors. The company also believes adjusted loss from operations is useful to investors to compare operating performance to the performance of other communications, entertainment and media companies. The company believes that investors use current and projected adjusted loss from operations to estimate the current or prospective enterprise value and make investment decisions.

Because the company funds and builds-out its satellite radio system through the periodic raising and expenditure of large amounts of capital, results of operations reflect significant charges for interest and depreciation expense. The company believes adjusted loss from operations provides useful information about the operating performance of the business apart from the costs associated with the capital structure and physical plant. The exclusion of interest expense and depreciation is useful given fluctuations in interest rates and significant variation in depreciation expense that can result from the amount and timing of capital expenditures and potential variations in estimated useful lives, all of which can vary widely across different industries or among companies within the same industry. The company believes the exclusion of taxes is appropriate for comparability purposes as the tax positions of companies can vary because of their differing abilities to take advantage of tax benefits and because of the tax policies of the various jurisdictions in which they operate. The company also believes the exclusion of stock-based compensation expense is useful given the significant variation in expense that can result from changes in the fair market value of the company’s common stock. Finally, the company believes that the exclusion of equity in net loss of affiliate (SIRIUS Canada, Inc.) is useful to assess the performance of its core consolidated operations in the continental United States. To compensate for the exclusion of taxes, other income (expense), depreciation, impairment charges and stock-based compensation expense, the company separately measures and budgets for these items.

There are material limitations associated with the use of adjusted loss from operations in evaluating the company compared with net loss, which reflects overall financial performance, including the effects of taxes, other income (expense), depreciation, impairment charges and stock-based compensation expense. The company uses adjusted loss from operations to supplement GAAP results to provide a more complete understanding of the factors and trends affecting the business than GAAP results alone. Investors that wish to compare and evaluate the operating results after giving effect for these costs, should refer to net loss as disclosed in the unaudited consolidated statements of operations. Since adjusted loss from operations is a non-GAAP financial measure, the calculation of adjusted loss from operations may be susceptible to varying calculations; may not be comparable to other similarly titled measures of other companies; and should not be considered in isolation, as a substitute for, or superior to measures of financial performance in accordance with GAAP.