What pulls best: emotion or logic?

I just read this care off Bob Bly.

It makes sense when you read it. Why do we see so little use of it in Brussels?

Let’s hit them with the facts, and in case they have not heard us, hit them harder, and just in case you are not sure they have heard you, hit them even harder.

Now, we know that does not work.

The alternative works. It may take you outside your comfort zone. But, hell it works. I wonder if anyone will try it?

***

Emotional appeal works best when you want people to take a
desired action. Excitement, urgency … whatever feeling might
inspire them to take action, giving people hard-core data will
usually not have the same effect.

A 2007 study conducted by Carnegie Mellon University tested
response to different appeals for donations for people in dire
living situations in Africa. The first appeal gave elaborate
statistics on the dislocation of millions of people, food
shortages, and the scarcity of rain in the region.

The second appeal talked about the story of a particular girl
who was starving in Zambia. A picture of the girl was sent
alongside, and students were requested to send donations
directly for her.

While the fact-focused appeal got students to donate $1.14 on an
average, the amount rose to an average of $2.38 for the
story-based appeal. A third appeal that contained both the story
and the statistics collected $1.43 on an average.

Source: The WordStream blog, 5/2/13.