How might we get people to willingly promote our product for free?

This sort of problem statement often comes up in CPS sessions. Unfortunately, more often than not, it doesn't make it through the group's convergent process and therefore gets rejected.

However, sometimes the question sticks around, and when it does, it is amazing what can happen. In this case Vancity Canada's largest credit union, co-developed the idea of offering public bicycles to the residents of one of the less wealthy areas. This means that people are now cycling around the city, advertising the firm, and helping to reduce pollution - hard to beat that as a PR result!

You can read more about the story here