We don't know the full stack powering this and there are 100K users/month. There have been a lot of great points in reply to this and I would like to add that

We don't know the full stack powering this and there are 100K users/month. There have been a lot of great points in reply to this and I would like to add that part of this cost may be to help perception. A service like this that feels/is slow can die pretty quickly if the perception of the service is that it doesn't work as well as it should.