"Frequent fliers may need a scorecard to keep track of what's served and sold in-flight.
Some airlines have tried to cut costs by eliminating meals, while others have attempted to boost revenue by selling them. Most carriers sell headsets for watching movies, and some rent digital entertainment units, pay-per-view movies or televisions. But others give headsets for free or don't charge for TV or satellite radio."

Airlines' food and in-flight entertainment policies

I don't really care if they sell food - does mean travellers will have to pack a nice picnic lunch - but providing plentiful WATER is an important safety issue in air travel. No plane should charge for water.