If I do you a favor, you probably will feel compelled to do me a favor, and then I will feel compelled to do you a favor again, and the cycle continues over and over. This principle is called reciprocity. Some microlending sites use reciprocity by having people donate to a specific project, rather than just donate to the overall organization. If FINCA would let you donate to a specific project, and then keep you updated on how that small business or individual paid back the loan to FINCA, you might feel compelled to donate again. You would be receiving information about how your loan has helped, and that information could persuade you to donate again in order to get more information and another "hit" of feeling that you're being effective and helpful.