As someone who firmly believes in a start-up's social mission, I would recommend getting on phone with a few Watsi clients (I am sure Watsi does it from time to time). It puts perspective on a lot of things.
You are making a lot of impact in these people's lives and they will let you know how much they appreciate it. On a website these people are somewhat distant story but talking to them is when you really share their experience. It will make you feel good (and somewhat worried) about what you are doing.
My wife and I sponsored a heart surgery for a child in Ethiopia with an organization we work with. The child's mother wouldn't let the child travel to get the needed surgery and that child ended up dying. Tragic.
They used the funds for another child, Kidest, and her photo is on our fridge for the same reason.
http://media.tumblr.com/c8a33a98917d46ca8d3220183dfd6e5e/tum...
because I know I'll click on it accidentally a few times a day.
I do it to remind me that there are more important things than whatever fire I'm currently fighting, and also simply because it makes me happy.