I had one article (in 4 years of writing) earn $43. Mostly though, I average $10-12 a month. So it covers my membership. I sometimes feel a little bit sad that in spite of writing more, getting more and more followers, and commenting more, I'm not making much. But then I realize the kinds of stories I write do have a much bigger payoff: when someone comments that my story struck a chord in them, brought back good memories, or otherwise lifted their spirit.
(Now if I had to actually make money on Medium, I'd be singing a different tune!)