Let's not forget the majority of the poor actually have jobs or are entrepreneurs.
About 60% of Colombia's economy
is informal. Which explains the low participation in health plans.
Here's a thought: when you run informal business, you can't really make use of the normal legal system, once you have a business related issue. You could, but that probably means you have to give up your illegal business or pay a huge fine for evading taxes. At least, that's the case where I come from (the Netherlands). The leaves a void for violent crime to enforce people to stick to business agreements.
When starting social business in a largely informal economy, this will can be of importance.
And let's not forget that the majority of the people in Caldas have money to spend: they can be the target group of a new product/service just as well as any other. On top of that, I think there must be a huge number of entrepreneurs whom's experience can be of great value to any social business solution.