Your mother told you this. Now science is catching up with her.
In the study, people who thanked others (by a hand-written note) were perceived as having warmer personalities and being worth forming a relationship with. Those who received these thank-you notes were more willing to cooperate by sharing contact details.
But you knew that.
If your organization isn't putting serious thought into thanking donors, you aren't really fundraising.
Thankful organizations are getting -- and keeping -- all the best donors.