The other day I phoned a popular restaurant to book a table for six. The receptionist asked me for my phone number (which is standard practice) and e-mail address (which is unusual). I soon received an e-mail asking me for my credit card details, with the warning that if I cancelled with less than two days' notice or was a no-show, the restaurant reserved the right to charge me HK$1,800.
This request came as a surprise, because it's not something I've encountered before in Hong Kong, although I'm aware it happens in other restaurant-dense cities such as New York and San Francisco. It's not a policy I like, because in these days of identity theft, who wants to give their credit card details by fax? But I understand the reasons behind it and realise it's not directed at people like me.
Popular restaurants have been forced to implement this policy because of selfish diners who make reservations at several places for the same day and time. This gives them the 'freedom' to pick where they want to eat at the last minute. Often these diners either forget to cancel unused bookings or simply lack the courtesy to do so. If a restaurant is left with a no-show before service has finished, there's no guarantee the table will be filled by a walk-in.
On the frequent threads that show up on food forums by diners annoyed at having to make table deposits, the posters rarely receive sympathy from other contributors. As they point out, if you were to book a seat on a plane and then failed to show up without warning, you wouldn't receive a full refund for the ticket after the plane took off without you. The same thing goes with tickets for the theatre or a movie - if you're a no-show, the performance will start without you and you won't be refunded. Fortunately for airlines and theatres, they already have your money, so if you don't show up it's your loss, not theirs. It's different with restaurants - they're operating on the good faith that the diner will be there when they say they will be; eateries don't make their money until you've eaten and paid the bill.
Restaurants operate on slim margins - the owners have to pay for rent, utilities, staff, equipment and the ingredients that go into the dishes. If a 50-seat restaurant had a six-person no-show, it could result in the loss of 12 per cent of that evening's income. If this happened several times a week, it'd put a serious dent in already slim profit margins.
It's just common courtesy to call a restaurant in advance to tell them you can't show up for the meal you've booked. You'd do it for other businesses, why not for someone you trust enough to feed you?