It depends on the goals of the self-published author. Amazon Kindle Unlimited (KU) is a subscription service that allows customers to read an unlimited number of books for a monthly fee. If an author's goal is to maximize their income from book sales, then KU may not be the best option, as KU authors are paid based on the number of pages read rather than the number of books sold. However, if an author's goal is to reach a larger audience and build their brand, then KU can be a good way to do so, as KU subscribers are more likely to discover and read an author's books. Ultimately, the decision to use KU or not will depend on an author's individual goals and circumstances.

For many authors, using KU is part of an overall long-term strategy for building an audience with the goal of eventually "going wide" outside of KU and on other platforms. It's worth remembering that Kindle Unlimited is only for ebooks and it's possible to combine strategies - going wide on printed books and limiting to Kindle Unlimited for ebooks.

Pros:

- Ability to reach a larger audience

- Opportunity to build an author's brand

- Monetary compensation based on page reads

Cons:

- Low payouts compared to book sales

- Unpredictable income sources