Selecting titles for off-site storage in a large library is sometimes a trip through the history of fads and passions. Years ago, I sent off a number of titles on atheism from the 1960s, thinking that subject probably wouldn’t be a craze again. Less than a decade later came Dawkins et al., so I’m definitely no seer.
However, I do have a proposal for the shortest-lived genre in book history: A Guide to [Whatever Subject] on the Internet. Ten or fifteen years ago this was a hot genre, and now the notion of using a book as a guide to websites just seems archaic.