A few weeks after donating to a youth literacy nonprofit, my friend Elena received a surprising email. It wasn’t the usual automated receipt or slick newsletter, but instead was a short video from a second-grade teacher. In the video, the teacher stood in her colorful classroom, holding up a book. “Hi Anne,” she said with a smile. “Thank you so much for your generous support. Thanks to you, my students were able to take home their very first books this year. You’re helping build lif...