There is one BE crossword puzzle which would be impossible without access to Chambers and its stock of very obscure words: "The Listener" puzzle which appears in the Saturday edition of The Times. To succeed with this crossword you really need Chambers and you also need a very extensive vocabulary of your own and a wide knowledge of modern life in the English speaking world. (Mrs Ecgberht and I have two copies of Chambers, an older edition and the current one, both heavily used in our attempts on The Listener. Sometimes we manage to solve it (working together) within a week, but not always.) Access to the internet and a good search engine could not usurp Chambers' role eg many of the solutions in The Listener do not appear in the online "Crossword Solver/ Anagramiser" websites or elsewhere. What proportion of the sales of Chambers comes from puzzlers is probably unknown - I would guess not too high.

An aside: a brilliant feature of Chambers is the etymologies it gives for nearly every entry - fascinating.

Another English dictionary containing words that are far from everyday is the "Official Scrabble Players Dictionary". Only Scrabblers would buy it.

I have the 1972 edition of Chambers Twentieth Century Dictionary which used to belong to my parents. I think they gave it to me when they bought a newer dictionary. We got it out every time Scrabble was played in my family.