Last month, I posted about reformatting my debut novel, Come Back . As part of the glow-up, I added a series link in the back matter, plus a QR code for the paperback, and a couple of sentences that told the reader which books contained stories of supporting characters (books 2 & 4). My goal was to improve series read-through. The e-book interior was updated September 12th and the paperback September 16th, so, the backmatter changed roughly half way through the month. I compared both Kindle e-book sales and Kindle Unlimited page reads by looking at total sales and page reads for each of books 2-4 and calculating what percentage they each were of the sales/reads of book 1. Ex: If I sold twenty copies of book 1 for the month and ten copies of book 2, read-through for book 2 would be 50%. Of course, I have no way of knowing whether the same reader bought all four books - or in the case of KU, whether customers were reading the entire series or even the entire book - but th...