1. Promises versus gifts
Prepared by J. Scott Armstrong (details on him at jscottarmstrong.com).
Please inform Scott about errors and also make suggestions (armstrong@wharton.upenn.edu)
Scott has taken these slides from adprin.com, a site that he founded. That site contains interactive versions of these
slides, along with linked references, videos, and webcasts, all in PPT and PPTX format that you can download.

2. Field experiment:
Mail survey response rates prediction case
A mail survey promised a $50 payment upon receipt
of the completed survey. Predict the percentage of
respondents, then go to the next slide for the answer.
Adapted from AdPrin.com 2

3. 23%
The same survey was mailed with $5.00
included. Predict the percentage of
respondents, then go to the next slidefor
the answer.

4. 49%
Note that promises do not work. People feel obligated to
reciprocate when others do something nice for them, not
when they promise to do so (Persuasive Advertising p 83-4).
To learn more go to AdPrin.com

5. Based on this exercise, write a small application step for
yourself, and set a deadline, preferably within one week. If you
are working with someone else, share your application plan and
the results of your application.
• For example, consider giving customers a small gift.
Adapted from AdPrin.com