Featuring huge numbers of people in need in fundraising materials serves to make the reader feel helpless.
Research shows that people who feel helpless give less money.
The Disasters Emergency Committee (DEC) didn't follow the standard route of focusing on the magnitude of the recent earthquake in Haiti in their appeals. They focused on what a donor could do with their donation.
It might not be perfect, but it's one of the best emergency ads I've seen in a long while.
For more thoughts on emergency appeals, Read Aline's post at Bluefrog Creative.