Some do. I think in the US it's somewhat common for many domestic flights still. It used to be way more common. http://www.flyertalk.com/forum/travelbuzz/86219

Some do. I think in the US it's somewhat common for many domestic flights still. It used to be way more common. http://www.flyertalk.com/forum/travelbuzz/862199-does-any-airline-charge-sell-headphones-anymore-they-always-free.html http://www.flyertalk.com/forum/travelbuzz/862199-does-any-ai... http://www.fodors.com/community/air-travel/headsets-on-delta-international-fee-or-free.cfm http://www.fodors.com/community/air-travel/headsets-on-delta... I've heard that also historically one of the big reasons for the odd jack was to prevent theft (back when headphones were relatively more expensive and all airline headphones were designed for reuse...)