So I had two books permafree, both of them the first book in three book series', and they've been like that for about 3 months- the equivalent of one amazon kdp select period. It's not been a success really, and now I'm thinking to go back all-in with select, for these reasons:
1- In that time the total number of books given away has been piddling. Minus promotion, it's less than 1000 copies per book, across all vendors. I'm thinking that I would give away that many using just the select free days- as normally just listing leads to almost 1000 free given away across the period, thanks to whatever boost amazon give. If I then double that up with promotion, it means all free given away in one concentrated location.
2- Then, after the free promo the book comes back in the paid charts at a better rank. It's nowhere near the bounce it used to be, but it still leads to paid sales. Those at least are people more likely to read it. Then the book will exist in also-boughts, however minorly, and attract the kind of readers who are accustomed to buy their books. As is, my free to second book in the series sell-through rate is below 1%. So the loss leader is not working, and it's invisible to anyone who won't scroll the free charts.
3- I wonder if this is an impact of the trend people here have been describing for a while, about free no longer being such a competitive edge. There are so many free books, and so many kindles are already stuffed to bursting. Someone said 99 cents is about as good as free, so I may price the opening books there. It's cheap still, but can still get paid chart visibility.
This post is in no way meant to be prescriptive, just sharing my thoughts. It could that staying with the other vendors for longer than 3 months may lead to more results, but I suspect not, considering I still have about zero reviews and almost zero actual sales on those sites, and I don't have the time to promote them indiividually. The name of this game is experimentation, so I'll go back in with select and see if I fare any better. Probably it will be about the same.