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 excess content payments over expense is variable based on the payment terms of our content agreements and is expected to continue to be significant as we enter into more agreements with upfront cash payments, such as original content agreements. Working capital differences include deferred revenue, taxes and semi-annual interest payments on our outstanding debt. Our receivables from members generally settle quickly and deferred revenue is a source of cash flow.

Cash provided by operating activities decreased $81.3 million, primarily due to increased payments for content other than DVD library of $835.1 million or 32%, as well as increased payments associated with higher operating expenses. The increased use of cash was partially offset by a $1,130.1 million or 26% increase in revenues.

Cash used in investing activities decreased $213.1 million, primarily due to a decrease of $242.2 million in the purchases of short-term investments, net of proceeds from sales and maturities. This decrease was offset by an increase of $15.6 million purchases of property and equipment.

Cash provided by financing activities increased $65.4 million primarily due to the $392.9 million net proceeds from the issuance of the 5.750% Notes in the year ended December 31, 2014 as compared to the $490.6 million net proceeds from the issuance of the 5.375% Notes less the $219.4 million redemption of our 8.50% Notes in the year ended December 31, 2013. This increase was partially offset by a decrease of $56.3 million from the issuance of common stock, including the impact of excess tax benefits.

Free cash flow was $393.5 million lower than net income for the year ended December 31, 2014 primarily due to $534.2 million of content cash payments over expense partially offset by $115.2 million of non-cash stock-based compensation expense and $25.5 million of favorable other working capital differences.

Free cash flow was $128.7 million lower than net income for the year ended December 31, 2013 primarily due to $227.9 million of content cash payments over expense and $45.3 million non-favorable other working capital differences. This was partially offset by $73.1 million non-cash stock-based compensation expense, $46.3 million in deferred revenue and $25.1 million loss on debt extinguishment, the cash impact of which is a financing activity and therefore not included in free cash flow.

Cash provided by operating activities increased $76.2 million, primarily due to an increase in revenues of $765.3 million or 21%. This increase was partially offset by increased payments for content acquisition and licensing other than DVD library of $502.6 million or 24% as well as increased payments associated with higher operating expenses. Operating activities were further impacted by increased payments for streaming delivery, payment processing fees and customer service call centers due to our growing member base.

Cash used in investing activities increased $11.2 million, primarily due to an