This excerpt taken from the SIRI 10-Q filed May 11, 2009.
Unaudited Actual Results of Operations
Our discussion of our unaudited actual results of operations includes the following non-GAAP financial measures: average self-pay monthly churn; conversion rate; average monthly revenue per subscriber, or ARPU; subscriber acquisition cost, or SAC, as adjusted, per gross subscriber addition; customer service and billing expenses, as adjusted, per average subscriber; free cash flow; and adjusted income (loss) from operations. We believe these non-GAAP financial measures provide meaningful supplemental information regarding our operating performance and are used for internal management purposes, when publicly providing the business outlook, and as a means to evaluate period-to-period comparisons. Please refer to the footnotes (pages 50 to 56) following our discussion of results of operations for the definitions and a further discussion of the usefulness of such non-GAAP financial measures.
The discussion of our results of operations for the three months ended March 31, 2009 and 2008 includes the financial results of XM from the date of the Merger. The inclusion of these results may render direct comparisons with results for prior periods less meaningful. Accordingly, the discussion below addresses trends we believe are significant.
Subscriber and Key Operating Metrics. The following tables contain our actual subscribers and key operating metrics for the three months ended March 31, 2009 and 2008: