In his recent book, “Retention Fundraising: The New Art and Science of Keeping Your Donors for Life,” Roger Craver outlines a study by Bloomerang.co that tracked that only 13% of donors drop off a file because of death. That means that everyone else is leaving for reasons that can be addressed by better relationships and communication. 5% thought the charity didn’t need them. 8% felt they had no info on how monies were being used.…