I measure how much readers enjoy stories by counting what fraction of readers who read the first chapter go on to the second chapter.  I call this the Reader Retention Ratio (RRR).  Things are tricky when the first & second chapters aren't released at the same time, but with a big enough sample size, you get a good idea how stories are ranked.  I had a big sample—counts for the first 40,000 stories published on fimfiction.  The average RRR was 0.71.

I test troublesome stories by releasing them on ponyfictionarchive.net or fanfiction.net and checking the RRR for each chapter.  "Moving On" is a troublesome story because there's no action and a lot of introspection.  It probably doesn't help that Twilight's problems in the story are problems most people don't even think about before their forties.  (It really should be tagged "mature".)

When I tested "Moving On", it had a reader retention ratio of 0.02.  That was the fourth-worst out of all 40,000 stories.  Readers liked 99.99% of the stories on fimfiction better than "Moving On".

After figuring that out, I wrote "Twilight Sparkle and the Quest for Anatomical Accuracy" and "The Saga of Dark Demon King Ravenblood Nightblade, Interior Design Alicorn".  They were fun stories and I'm proud of them, but it made me a little sad to think that I had to give up the idea of writing stories like "Moving On", that they just couldn't be told.  I'm not under the illusion that it's a great story, but it is the kind of story I wanted to tell, about the kinds of things I worry about.

Now, almost a year later, it's on EqD.  I don't think stories like this will ever be tremendously popular, but maybe they can at least be told.