You have a restaurant.
It has been recommended to me by someone whose opinion I trust (he's a good chef himself, plus is one of the party I'm booking for).
So I'm calling the number on your website (comments reserved!) to book and make a reservation for tomorrow.
You haven't answered the phone on any of the first four attempts. It's not engaged, so I know that either the number is wrong (I shall consult the phone book shortly), or you are not there - or worse, you are there, but not answering.
Luckily I'm probably going to persist until I get hold of you. I wouldn't normally - nor will a lot of customers. Tip - buy an answering machine. Heck, Amazon have one for £3.95 on special offer - here.
There is no excuse.