Sarah Weinman's take on the demise of Book World as a special section of the Washington Post says it all. I'd just like to add a personal note.
Book World was my first date as a book reviewer. Byron Dobell, the king of editors, who ran the section from the offices of the New York Herald Tribune (it also appeared in the Washington Post and the Chicago Tribune), asked in the late 1960s if I'd like to be his mystery reviewer. I was of course delighted, although my mother said when I told her, "Mystery reviewer? Why can't you use your real name?"
It was in many ways the best job I ever had. Not only was the legendary Bleeck's bar of Breslin fame just downstairs, but I got to do a regular crime column, and also had the chance to contribute (for real money) other pieces. Interviewing Kingsley Amis on his reading habits, I was surprised by his admonition: "Never read fiction before noon."
So, bye bye Book World -- which I'll continue to read online. And Byron, now a very successful painter, thanks for the memories.