Stable income: Somewhat stable

Amazon KDP, which allows individuals to self-publish books, can provide a moderately stable income source for most people. Based on online research and personal observations, while some experience fluctuations, many authors earn consistently over time. There is a decent baseline income potential, although it may not be entirely predictable every month. I'd rate it a 3 out of 5 because it offers a reliable income for many, but there can be some variability that may require additional effort to manage.