Elephantiasis and Philanthropy

The CEO of GlaxoSmithKline has spent a couple hundred million dollars to fight Elephantiasis in third-world countries. He has also spent countless hours promoting and working on the project. It's great that a person and company are so willing to help mankind. However, is philanthropy smart, economically speaking? There are benefits (good PR and that warm, fuzzy feeling), but there are also costs. I once heard someone say that Bill Gates has done more collectively for the world by creating jobs and personal computers for millions of people than Mother Teresea did for the few thousand lives she individually touched. What do you think?