I read this in two sittings several months apart. The first time, I got to the choose-your-ending part within two days and stopped there because I knew which ending I wanted as my canon one, but wanted to read all three and was afraid doing so would ruin the emotional experience. When I finally picked the book back up, I read from beginning to end, including all three choices, in less than a day. Reading the other two endings temporarily took the shine off my "real" one, but I'm glad I chose well (not that the right choice wasn't set up to be clear, which I also liked as an authorial decision). I hope I'm able to right a full review for this someday—I loved the innovative format and the brutality with which it was used.