(CNN) -- You know the old saying -- if a deal is too good to be true, then it probably is too good to be true.

That's what happened to a major retailer's online shoppers Friday afternoon.

Sears.com inadvertently advertised Apple's 16GB iPad 2 for $69, much less than the regular advertised price of $744.99.

That low price got the attention of web shoppers and the deal went viral on Twitter and other social media websites.

Many people took advantage of the unbelievable deal, though a Sears spokesperson couldn't give an exact number.

Friday night, Sears posted a statement online telling customers the error was made by a third-party vendor and the deal will not be honored.

"We want you to know that, unfortunately, today one of the Marketplace third party sellers told us that they mistakenly posted incorrect pricing information on two Apple iPad models on the Marketplace portion of the website. If you purchased either of these products recently, your order has been cancelled and your account will be credited," the statement said.

Paula Knight of Riverview, Florida, was one of the disappointed customers. Her son has Asperger's syndrome and relied heavily on his iPad for his schoolwork, until it was stolen a few months ago.

So when Knight's friends told her about the great deal on Sears.com, she said she jumped on it.

Knight said immediately after she paid for the iPad, she received e-mail confirmations from both PayPal and Sears.

About six hours later, Sears sent her an e-mail to tell her that her order was canceled because of the mistake.

"I shop online all the time and I've never had anything like this happen," Knight said. "They want to blame a third party, but the order confirmation e-mail I got was from Sears."

"They are a huge company I thought I could trust and rely on," Knight said. "But if they don't honor this, I won't ever shop at Sears again. I just want my order honored."