GiveWell exists because most charity goes horribly awry since it is based on impulsive fuzzy-based giving that pays attention to the 'do something' and 'warm fuzzies' factors, and doesn't focus on maximizing impact. Doing something like this carefully could easily move it orders of magnitude in expected impact, and such care could be prevented with a rush of impulsive moves that poison the waters and favor a relatively inefficient approach even if successful in moving money.