Free gift, part 2.

The philanthropic organization of Exercise 42 decided to go ahead with the new gift. In mailings to 98,000 prospects, the new mailing yielded an average of $0.78. If they had decided based on their initial trial not to use this gift, what kind of error would they have made? What aspects of their initial trial might have suggested to you (as their consultant) that a larger trial would be worthwhile?