activities generally corresponds to our net sales. Because our customers primarily use credit cards to buy from us, our receivables from customers settle quickly. 

Cash used in investing activities corresponds with purchases, sales, and maturities of marketable securities, cash flows from acquisitions, and purchases of fixed assets, including internal-use software and website development costs. Cash used in investing activities was $333 million, $778 million, and $317 million in 2006, 2005, and 2004, with the variability caused primarily by purchases, maturities, and sales of marketable securities. Capital expenditures were $216 million, $204 million and $89 million in 2006, 2005 and 2004, with the sequential increases primarily reflecting additional investment in development of new features and product offerings on our websites, as well as investments in fulfillment-related assets and technology infrastructure. Capital expenditures included $108 million, $79 million and $44 million for internal-use software and website development during 2006, 2005 and 2004. Stock-based compensation capitalized for internal-use software and website development costs does not affect cash flows. We also made payments, net of acquired cash, of $32 million, $24 million, and $71 million in 2006, 2005 and 2004 to purchase certain companies. 

Cash used in financing activities was $400 million, $193 million, and $97 million in 2006, 2005, and 2004. Cash outflows from financing activities result from repurchases of common stock, repayments of long-term debt, and payments on capital lease obligations. We repurchased $252 million of our common stock under a $500 million repurchase program authorized by our Board of Directors in 2006. Repayments on long-term debt and payments on capital lease obligations were $383 million, $270 million, and $157 million in 2006, 2005, and 2004. Repayments on long-term debt include €250 million and €200 million of our 6.875% PEACS for $300 million and $265 million in 2006 and 2005. Additionally, we repaid $154 million to redeem a portion of our 4.75% Convertible Subordinated Notes in 2004. See Item 8 of Part II, “Financial Statements and Supplementary Data—Note 4—Long-Term Debt.” If all of our capital leases were classified as operating leases, the detriment to cash flows from operating activities would have been $21 million, $2 million, and $4 million in 2006, 2005, and 2004. Cash inflows from financing activities primarily result from proceeds from exercises of employee stock options and tax benefits relating to excess stock-based compensation deductions. Cash inflows from proceeds from exercise of employee stock options were $35 million, $59 million, and $60 million in 2006, 2005, and 2004. Cash inflows from tax benefits related to stock-based compensation deductions were $102 million and $7 million in 2006 and 2005, in accordance with adoption of SFAS No. 123(R). We expect cash proceeds from exercises of stock options will continue to decline over time as we continue issuing restricted stock units as our primary vehicle for stock-based awards. 

In 2006 and 2005 we recorded net tax provisions of $187 million and $95 million, and