It doesn't matter how many administrators you have, you need more if you bill people and less if you don't. This would apply to private or public sectors. Don't you think this has something to do with why we see private companies giving away stuff instead of implementing microtransactions?

The obvious problem with providing stuff at no charge is that it will cost too much to supply it, and people will waste it, but that isn't what I would call overhead, and I don't think you are talking about that.