Suncare, a wholly owned U.S. sales subsidiary of Soin de Soleil, a French corporation, purchases a variety of skin care products from unrelated U.S. suppliers and sells them at a profit to unrelated distributors in Europe. Suncare also manufactures cosmetics in the United States and sells them to unrelated distributors in Europe. Finally, Suncare purchases a computer from an unrelated U.S. supplier and resells it at a profit to Soin de Soleil, which will use the computer in its treasurer's office in Paris. Title on all of the sales passes from Suncare to the purchaser at the international airport in France when the goods arrive. What is the source of the income realized by Suncare from these transactions?