For example, my newly published book, Signs of Trouble, is an exciting story (I hope) but the included educational activities are intended to help kids learn safety and reading skills and to understand others with special needs.
However writers often never know how things they've written have influenced others. Sometimes even the readers themselves don't realize that something in a book or article has made a tiny difference that will ultimately combine with other influences to make a big change in their attitude or behavior.
When we are aware that something we read has helped us, if only in a small way, letting whoever wrote it know would make a positive difference in that author's own life.
Since this is the season of Thanksgiving why not send an e-mail message or even an old-fashioned letter to someone whose writing has been helpful to you?