I’d certainly be interested in seeing how the experiment goes. I can think of various pros and cons. On the con side, in real terms you are going backwards, and it’s unlikely that those who click on the ad are going to be paying Medium members, so there’s not even that chance of a slim defrayment of the ad cost.
On the pro side, it’s more exposure, and if timed right could slide an article from “also-ran” to “viral” depending on how Medium works their algorithms.
Another variable is just how good the ad itself is. Make it a good teaser and the cost per view will drop as more and more readers click on it. The usual advertising variables of target audience could also have a big impact.
So my initial comment was a teeny bit tongue in cheek, but I can see how a good ad buy might pay dividends, especially in building exposure. It’s not quite so cut and dried as I made it sound, and I hope you follow up this article with more advice based on experience.
I’m tempted to give it a try, myself!