In 2014 I moved from Sydney to Brisbane. One year later I moved from Brisbane to Sydney. I have a mail redirection with Australia Post for the old Brisbane to current Sydney address. However, I have recently allowed my address forwarding from Sydney to Brisbane to expire because the result was too many mail redirection orders in with Australia Post.
What does this matter to charities? My charity mail has virtually dried up, with the exception of a couple of charities who appear to have performed data hygiene and who have matched their file with the Australia Post PAF file. This matching allowed the charities to learn of various moves where the mover opted into commercial organisations (including charities) to learn about their new address.
How many people on your file are similar to me? How many donors have you lost touch with simply because they did not share their new address with you and because your organisation does not have a best practice data cleansing process in place? You may have a stellar donor acquisition program in place, but if you do not take the time to ensure those donors stick with you (or at least you keep current with their whereabouts), the acquisition program is not worth bragging about.
Read more about data hygiene here.