I think this would be a great pricing model if applied to tutoring for students. If you find a tutor useful, you'll go back to them. Conversely if you find th

I think this would be a great pricing model if applied to tutoring for students. If you find a tutor useful, you'll go back to them. Conversely if you find they weren't helpful, you leave early. So it's up to the tutor to entice you to come back by providing value up-front. However, the primary difference is that you do this logarithmic scaling per student rather than as a set price for everybody.