At Booked Up one of our favorite eccentrics was a gentleman we called the "little book" man.
Once or twice a year this customer would show up at the shop with a ruler and work his way around the main room, measuring the books.
He was not cheap in the least, and seemed to have no exact height limit. Every time he showed up he spent $2,000 at least, and often more. He never said much - indeed, I can't recall him sayinganything. But he always went away carrying a box of short books. [Books: a memoir, p 138]
I mentioned this to Thom Hickey yesterday in the context of an ongoing conversation about bibliographic data and the size of books.
The dimensions of a book are an important piece of metadata for some; if you are shipping books it is useful to know in advance what size they are. It also provides an example of how requirements can change over time. I was talking to somebody involved in an offsite storage facility a while ago where they had to measure incoming books who said that it would be so nice if they consistently knew the heights of the books from the metadata.
I wonder what they guy wanted the short books for ;-)