Re: Buy e-books or subscribe to Kindle Unlimited?
I do both. I have a Kindle Unlimited subscription and buy e-books from Lybrary.com.
I like both, but the book itself has to catch my interest. With KU I am very selective as I hate to waste my time even though they are 'free' if that makes sense. E-books from a good site are also nice as the usually will hold your virtual library for you.
Some successful authors had blogs where they slowly released their material (after hooking their audience) with great results. See John Dies at the End
as an example.