I am also an avid Kindle user. I signed up for freebooksy.com about five years ago. You enter the kind of device you have and the genre(s) of books you enjoy reading. Every day, I get an email with 6-9 free books and one special 99 cent sale on one featured book. I have "discovered" many new authors this way and if I select a book I don't like, I just delete it. I do take the time to enter reviews of the books I read, especially yhe very good ones. I have somewhere around 3500 books in my library now and I just download them when I want to read them. The one improvement I wish they had is a brief synopsis of each book so when I go to the library I can review them as I select my next book to read. If I get book one of a series and I really like it, I buy the remaining books it that series. Other than that, I've only had to pay for about five or six books in the past five years.