I’ve not changed the price of my first book on Amazon in a year and a half. My guess is that frequent price change or even free days will not do much for your sales and won’t result in many new reviews. Nonetheless, I thought I’d make my book free for a day and see what happens.
The day is about half over, and per the KDP report Amazon offers, I’ve had about 70 downloads. Given that I barely advertised it — a few tweets only — that is not too surprising. But there are a few surprising things.