A relatively recent movement called Effective Altruism has been shaking up philanthropy. The premise is simple: People are concerned how much good the money they allocate toward charity is actually doing. Usually the metric people like to look at is the amount of money a charity spends on overhead, but this is a very gross metric. Yes, a charity that spends almost all its money on overhead is almost certainly criminally ineffective, but for two given charities that spend the same amount on overhead, one may do a lot more good than the other.
Effective Altruism instead looks not only at what percentage of a donation gets to the ground, but what it actually does when it gets there. Organizations like GiveWell look at a host of metrics to determine which charities save the most lives for a given amount of money, and rank them accordingly.