There is a specific experience of reading a book that you bought because the cover was beautiful and then discovering that the book deserved the beautiful cover. Not that covers always predict content — they don't — but occasionally the design understands something about the book that turns out to be correct.

The cover of the Virago edition of Penelope Fitzgerald's The Gate of Angels has a 19th-century illustration that is both completely decorative and somehow exactly right for a novel about Cambridge and physics and the way belief persists in skeptical environments. I bought it because the cover was beautiful. The cover was right.

This is the best case for buying books in physical form. The object is part of the experience in ways that ebooks, however convenient, cannot fully replicate.