From  WhySoWrong Tales From Retail:

The Saving

Years ago on a busy Black Friday morning at "Save Money, Shop Elsewhere" I overheard two customers complaining about a competitor as they waited in line for cheap games.

It seems the competitor advertised some half priced brand name portable GPS units. Must have thought their normal customer market needed directions from their desk to the supply closet since they sold office supplies.

The competitor formed a neat and orderly line outside the store in the snow and ice. They handed out nice numbered reservation slips for the 50 or 60 people waiting half the night in the cold.

They then opened right on time and sold both units they received.

That's right. 2. They had 2 GPS in stock.

I get the customers attention, ask if they kept the info. They had.

Me: I've got 25 in stock. Want me to match that ad for you?

Customers basically speechless but extremely happy when they both get the GPS they wanted. A few customers later in our sales line also got some.

The ruining

Hours later word must have gotten around that we stocked that unit all the time . The competitors price was well below our cost, so each unit sold as a single item sale would be a significant loss of profit. Time for the eBay resellers.

The phone begins ringing every few minutes as we enter the last hour of the sale. Repeat same phone call over and over.

C: Do you have competitor portable GPS?

Us: Yes and no.

C: What?

Us: We have ??? units available at $$$FullPrice$$$. We gladly matched competitor price this morning for anyone who came to participate in our sales event. We are well aware that competitor has been out of these since they opened their doors this morning. As there is no way for them to sell you a unit, we are not price matching the sale this late in the day.

C: Oh... Nevermind then.

TL&DR

Competitor screwed customers advertising things they didn't stock. Sold our stock below cost to customers who spent night waiting for our sales. Did not sell our stock to customers calling in last minute.

-- WhySoWrong