I started a spreadsheet about 5 years ago to list all the books I read, both DTB or my preferred method via kindle. The reason I started with a spreadsheet was because my eldest son gave me a kindle in 2010, I was just divorced and had to manage a very tight budget, with 2 younger children and I was on a low income. In 2010, I spent $50 and fell in love with ebooks. Now my children are grown, I have a great job and my book budget is $1000 a year. I busted my annual budget last year by $200, but over the 10 years, I am still under budget. Importantly I know every book I've bought, and I rate and review each book for my own purposes. I've tried collections, and do use Goodreads but my spreadsheet is the best. I use it to re-read those books I bought years ago. I back it up as I can't bear the thought of losing it - Ha Ha.