Here's my take. I'm totally new to KU so I don't even know if this KU read stat is good.
I used Reading Stacks on May 7th, but it was part of a very large launch promo with other sites including Bargain Booksy & ENT the days prior. And on my day with Reading Stacks, I was simultaneously running Red Feather Romance & Fussy Librarian. I got just shy of 1k reads at 998 page reads the day of the promo. My record is 1370 three days later. I averaged about 1k throughout the week.
It's so difficult to ascertain where the page reads are from. And, KU readers have never heard of me until 2 weeks ago as my other three books are published wide. That's got to impact it, right? Interestingly, I sold the highest the day of Reading Stacks at 58 sales, but I really think a lot of the sales was due to Red Feather Romance.
The whole page KU thing is an experiment for me and, so far, I'm not all that impressed. I could have landed the same $ in sales wide with my launch but the hope is for a tail, extra exposure, and possibly more reviews. I also understand that KU elevated my rank. I'm keeping an eye on my reads but if it doesn't add up in 3 months, I'm returning my book to wide. Hope my stats give you some idea.