Installing automatic payment machines at mikvaot in Jerusalem has resulted in a 20% increase in revenue. It appears that many mikvah ladies are not such great tzadekot (?) since it is presumed that they were pocketing quite a bit of shekels!
Source here. (Sad, but funny at the same time, is the story about an obese woman who got stuck in the new revolving door of a mikvah. She was stuck for 15 minutes, and it took another ten minutes to free her. Since this was the only entrance, there was a long line of women waiting to get in and many just gave up and went home.)