From now until January 10 Amazon is having a promotion for Amazon Affiliates (like me). If you are unaware, any purchase that you make after having clicked through on of Bookwi.se links (whether it is what I liked to or not) gives Bookwi.se 4 to 10% depending on what you buy and how many other referals that resulted in a purchase earlier that month. (I disclosed Bookwi.se income and expenses in this post.)
I personally have been an Amazon Prime member for just over 2 years now. In addition to being a replacement for Netflix for me (which would be $8 a month), I also can borrow one book a month from the Kindle lending library. I do not borrow a book every month, but I borrowed about 7 or 8 books this year. Also starting last month Amazon allows Prime members to purchase (for free) one of four pre-release books each month through the Kindle First program.