If I had to implement something like that, I would make sure that the recipients of these acts of kindness were chosen uniformly at random from the entire workf

If I had to implement something like that, I would make sure that the recipients of these acts of kindness were chosen uniformly at random from the entire workforce, and that the times between acts of kindness were exponentially distributed random variables. It would just feel right to be able to say that our "random acts of kindness" are a Poisson process. Or better yet, abandon the entire idea and get a rock climbing wall instead. I love those things.