I quoted $20 per disability-adjusted-life-year (http://en.wikipedia.org/wiki/Disability-adjusted_life_year). That means for $1000 you could allow one child who otherwise would have died an infant to live into old age, extend the lives of 10 people by 5 years, etc.

I earn a pretty good salary in a developing country. 'Pretty good' is quite relative and would be minuscule compared to salaries in the developed world. But - I live a comfortable life here, and 10% of my monthly salary I donate is sufficient to support 2 kids for schooling, lodging and food.

So, yes, starting small means a lot, and it doesn't need to be a huge amount at all.

their whole lives