In July, Amazon made its Kindle Unlimited subscription program for e-books and audiobooks official. And, based on the money Amazon's paying out, the program is getting off to a solid start in the U.S.

Working off of early trial response, Amazon is adding a bonus of $2.7 million in August, on top of the regular base fund of $2 million. The extra cash will be divided among the most popular Kindle Direct Publishing authors and titles. Going forward, these popular books and authors will be identified as KDP Select All-Stars on the applicable KDPS title’s detail page.

The top 100 KDPS authors in August will receive bonuses ranging from $25,000 (for the 10 most-read authors), down to $1,000. The top 100 KDPS titles will earn between $2,500 (for the 10 most read books), down to $500.

Acknowledging that authors outside the U.S. have not been able to benefit from the growth of KU, Amazon also added an additional bonus of $80,000 to be paid out on all KOLL loans outside the States.