I used to read only physical books, but when I got into audiobooks I noticed I had a digital trail of the books I was reading. I started to recording them in a spreadsheet. Eventually I was able to bring that into Goodreads as a way to get algorithmic recommendations based on past reading habits. I do not see that works very well, however. Bookwyrm seems to work differently. It is more of a social network and it helps you find new books to read by finding other readers with similar interests to yourself.