The early birds got the deal with Best Buy's MasterCard promotion earlier this week. Others went home disappointed.

On Monday, the Richfield-based electronics retailer sent an e-mail to its Reward Zone members who are also MasterCard holders with a coupon offering $50 off a purchase of $100 or more, if they paid with a MasterCard.

The offer, which was to be good through Sunday, had a lot of exclusions (not valid on Apple iPods, Blu-ray players and certain other products), but it had two huge loopholes through which many bargain hunters jumped.

It allowed consumers to use the offer on gift cards at iTunes, Amazon or Best Buy, and it had no limit on the number of cards that could be purchased.

The unprecedented offer went viral on deal sites such as Slickdeals on Monday, and a few early customers made off with Amazon and Best Buy gift cards worth up to several thousand dollars, according to Consumerist.org.

According to Best Buy, which has 40 million Reward Zone members, the company realized its targeted coupon was incomplete and sent in error. It canceled the offer later on Monday, said Best Buy spokeswoman Amy von Walter.

A new coupon was issued for use on Monday only, valid on a single, regular-priced item of $100 or more, with iTunes, Amazon and other gift cards excluded and a limit of one coupon per household. "We regret any confusion it created," von Walter said.

Some customers and consumer experts are crying foul.

"To circulate an offer and make sure it's in the public domain and circulated widely and then change the terms and conditions is not sound business sense," said Hal Stinchfield, founder and CEO of consulting firm Promotioninsights.com of Orono.

Tammy Caballero of Woodbury heard about the deal from a post on TheCouponHigh.net and printed the coupon. But by 7 p.m. when she went to the store in Oakdale, the cashier told her about the changes in terms.

"Darn, I wasn't fast enough," she said.

The three printer cartridge packs that she planned to purchase for $34 each were rejected under the new offer, which specified that each item had to cost $100 or more, not a total of $100.

Dan Hendrickson of the Better Business Bureau of Minnesota thinks consumers and businesses need to view the issue through a prism of what is fair and reasonable.

"So long as the offer wasn't used as a hook to get customers in the door to profit unfairly or illicitly, which they weren't, they're allowed to make mistakes," he said.

John Ewoldt • 612-673-7633