This report describes insights gleaned from the Data Fellows collaboration among PayPal, Northwestern University’s Kellogg School of Management, the Golub Capital Social Impact Lab at Stanford University’s Graduate School of Business, and ImpactMatters. By embedding researchers in PayPal’s charitable giving team, we co-designed and executed experiments to generate generalizable knowledge about donor behavior. This report describes the results of several experiments focused on answering the question: Does information about the cost-effectiveness, or “impact,” of a charity increase donations? We find, across different contexts and for both well-known and lesser-known charities, that cost-effectiveness information increases micro-donations. We discuss the implications of these findings for nonprofits and platforms trying to improve charitable giving.