The future of your book depends on how it’s published. The way it performs the first few weeks to a month gives data to Amazon telling if it’s either a best seller or a flop.
The number one factor Amazon measures is sales. The more sales you can get, the better. Amazon’s system doesn’t separate free books from books purchased at cost.
At the minimum, you must give your book out for free for five days using the Kindle Direct Publishing five day free promotion, which is available every 90 days. Statistically, books priced at $0.99 sell better than other prices. Pricing your book higher lowers the amount sold. The first month it’s best to price it at $0.99.
If your book is slow to gather reviews, use Amazon approved methods such as:
NOTE: Another method is to run the five day promotion every other day. Results in my tests are the same at the end of the month for either method.