I remember during the "heyday" in SF when all the restaurants were filled with customers it was often common for people to make reservations for dinner at more then one restaurant. They would then decide at the last moment which restaurant they really wanted to go to.

That was so unfair to the restaurant where they were a "no show" and to customers that couldn't get reservations at said restaurant.

Finally some restaurants started insisting on a credit card # when dinner reservations were booked and one was advised there would be a charge if you were a "no show".

I haven't heard of any restaurant doing that for quite awhile but at the time I sure understood the reason why some of the restaurants instituted that policy.

Consideration from the business AND from the customer sure makes life more pleasant for everyone.

I have had to provide my credit card number many times for restaurant reservations... very common in Las Vegas and other popular destinations.
Maybe it is because I usually book for 4 or more...?