henry copeland:

Donation Psychology: “Even a Penny Will Help” | Social Psych Online

They approached 84 people—42 were just asked for a donation and the other 42 were also told that “even a penny will help.” For people who chose to make a donation, the average amount they gave was the same in each group, but still, the “even-a-penny” version of the request pulled in $30.34 in total donations whereas the basic request pulled in $18.55.[1]
- socialpsychonline.com