Demand for Southend United merchandise has gone up by more than 400 per cent since the Blues' triumph over Manchester United last week.
The club has taken the unprecedented step of reprinting Tuesday night's programme after its phones rang off the hook with fans desperate to get their hands on a cop of what may one day be a collectors' item.
And it has also sent back its Road to the Fourth Round T-shirts, so they can be reprinted with a picture of the scoreboard showing the Blues' 1-0 winning scoreline.
Commercial manager Brian Wheeler said he decided to print another 2,600 programmes after the first run of 6,000 sold out before the match had finished.
He said: "They are going like hotcakes. We have never seen it before.
"We have had non-stop calls for the programmes.
"It started during the match. A lot of people were turning up not having a ticket for the game, but wanting a souvenir of the match."
He added: "It has been a hard two or three weeks. Since the draw was made, we have been working around the clock. It has been hard work, but fun."
Steven Ladd, who works in the club shop, said the number of internet orders for shirts had rocketed from ten a day to 40 or 50.
"It has been chaos," he said.
"At the moment, I have got about 100 sitting in the inbox waiting to be processed.
"Freddy's shirt has always been our top shirt seller, but we have seen a sudden increase in goalkeeper shirts with Darryl Flahavan's number on it."
The club is also launching a souvenir poster of the historic match, which is already on sale.
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