The following tables present our key performance indicators for the periods presented.

(1) EBITDA and Free cash flow are non-GAAP financial measures. See “Non-GAAP Information” below for our definitions of, and additional information about, EBITDA and Free cash flow and for a reconciliation to the most directly comparable U.S. GAAP financial measures.

Non-GAAP Information

In addition to our results determined in accordance with GAAP, we believe the following non-GAAP measures are useful in evaluating our operational performance. We use the following non-GAAP financial information to evaluate our ongoing operations and for internal planning and forecasting purposes. We believe that non-GAAP financial information, when taken collectively and in context, may be helpful to investors in assessing our operating performance and trends and in comparing our financial measures with those of comparable companies that may present similar non-GAAP financial measures.

EBITDA and Free Cash Flow

We define “EBITDA” as income (loss), plus (minus) depreciation and amortization expenses, plus (minus) interest, plus (minus) taxes and “Free cash flow” as net cash from (used in) operating activities less capital expenditures. EBITDA and Free cash flow are intended as supplemental measures of our performance that are neither required by, nor presented in accordance with, GAAP and these measures should not be considered a substitute for net income (loss), and net cash used in operating activities reported in accordance with GAAP. Our computation of EBITDA and Free cash flow may not be comparable to other similarly titled measures computed by other companies, because all companies may not calculate EBITDA or Free cash flow in the same fashion.