Why Advertise?

So with my last blog I talked about how advertising works and it gets people through the door of your company that want to buy that product.  So what happens when the company doesn't have the product in stock?  Well from experience I can tell you what happens.  Our company launched a new product at the beginning of April.  We put up signs and advertised for it so we could get people to come in and reserve one.  The advertising did work and it brought in a lot of traffic to our store, but since we have gotten the reservations we have only received 8 of them since Mother's Day weekend.  We have more than 8 reservations to uphold to so when the customers call us asking when their product will be in we can't even give them an honest answer because no one truly knows.  Sometimes the customers understand this and other times they don't and we get yelled at.  So why advertise a product that you don't even have enough quantity of to fulfill peoples reservation?  You have customers coming in excited for the product, but you have to tell them that we don't have any in yet and were not sure when were going to get more in.  In all honesty, company's should have enough of the product on hand and prepare for the worse before they decide to advertise a product and say that they are in the stores now.