Every year, university alumni receive an envelope in the mail, asking them to donate to their alma mater. Donors to a charity are sent heartfelt letters, asking for donations to support a worthy cause. While these correspondences are considered pesky by some, they are effective and ensure an organization keeps running. One question you might have as someone who receives these letters: how does an organization know who to contact for donations? With limited resources, how do they ensure their donor outreach is effective?