Maybe it's because I'm semi-technical, but "$0.001 each" is clearer to me than "1 cent for every 10 uses." I mean, I recognize that they're synonymous, but the

Maybe it's because I'm semi-technical, but "$0.001 each" is clearer to me than "1 cent for every 10 uses." I mean, I recognize that they're synonymous, but the former clicks in my mind faster than the latter. So, if, as you admit, the service's audience is semi-technical, and if the average semi-technical person's brain works like me (big assumption, I know), I would argue that they should stick with $0.001.