$200.0 million of Senior Convertible Notes. The Senior Convertible Notes consisted of $200.0 million aggregate principal amount due on December 1, 2018 and did not bear interest. In April 2013, we exercised our option to cause the conversion of the Convertible Notes into shares of our common stock. See Note 5 of Item 8, Financial Statements and Supplementary Data for additional information.

Our primary uses of cash include content acquisition and licensing, streaming delivery, marketing programs and payroll. Payment terms for certain content agreements require more upfront cash payments relative to the expense and therefore, future investments could impact our liquidity.

We expect to significantly increase our investments in international expansion and in streaming content, particularly in original content. As a result, and to take advantage of the current favorable interest rate environment, we plan to obtain at least $1 billion in long-term debt in the first quarter of 2015. Our ability to obtain this, or any additional financing that we may choose to or need to obtain, will depend on, among other things, our development efforts, business plans, operating performance and the condition of the capital markets at the time we seek financing. We may not be able to obtain such financing on terms acceptable to us or at all. If we raise additional funds through the issuance of equity or debt securities, those securities may have rights, preferences or privileges senior to the rights of our common stock, and our stockholders may experience dilution.

As of December 31, 2014, $130.8 million of cash and cash equivalents were held by our foreign subsidiaries. If these funds are needed for our operations in the U.S., we would be required to accrue and pay U.S. income taxes and foreign withholding taxes on the amount associated with undistributed earnings for certain foreign subsidiaries. As of December 31, 2014, the amount associated with undistributed earnings for certain foreign subsidiaries for which we could be required to accrue and pay taxes is $29.2 million. See Note 10 of Item 8, Financial Statements and Supplementary Data for additional information.

Free Cash Flow

We define free cash flow as cash provided by operating and investing activities excluding the non-operational cash flows from purchases, maturities and sales of short-term investments. We believe free cash flow is an important liquidity metric because it measures, during a given period, the amount of cash generated that is available to repay debt obligations, make investments and for certain other activities. Free cash flow is considered a non-GAAP financial measure and should not be considered in isolation of, or as a substitute for, net income, operating income, cash flow provided by operating activities, or any other measure of financial performance or liquidity presented in accordance with GAAP.

In assessing liquidity in relation to our results of operations, we compare free cash flow to net income, noting that the three major recurring differences are excess content payments over expense, non-cash stock-based compensation expense and other working capital differences. The