The lesson for today is that while it’s great to make friends with a coupon promotion, you’d better realize that those friends have other friends—and they don’t mind sharing.

California-based quick service chain Carl’s Jr. found that out last week when they ran a promotion at a Los Angeles Lakers basketball game offering a small group of contest winners a reasonable prize: the chance to get texted a code to input in a specific spot on the Lakers Web site that would let them access a printable coupon for a free Carl’s Jr. burger.

It all seemed manageable enough. The text only went out to 276 contest winners during that one Staples Center game with the New Orleans Hornets. (Don’t ask me what these 276 won to earn their prize, because I don’t know and can’t find out.) The page on the Lakers web site was only open for 48 hours, and the participating Carl’s stores were ready to accept the paper coupons.

And yet, and yet. A day after it kicked in, the promotion was cancelled, the Lakers Web page connected to the promotion was closed, and at least some of the Carl’s Jr. outlets were posting signs saying that the coupons would not be honored because they had been “seized from a secured Web site and distributed illegally.”

According to press reports, the promotion was halted after 50 redemptions. I’m not certain how 50 coupons from an expected redemptions pool of 276 tipped Carl’s or its parent CKE Restaurants that something had gone awry. Maybe someone presented a coupon in the 12 states other than California where Carl’s has outlets.

More likely, someone from the company or one of its agencies was monitoring the Web or just doing a Google search and saw that the limited-circulation coupon code was in fact making the rounds of the many, many Web sites focused on aggregating coupon deals and free stuff. Once released into the wild, the code just spread logarithmically. You can’t stop the march of free food across the Internet.

According to a blog report, Carl’s says it will still honor coupons from presenters who can show that they were actually at that Lakers-Hornets game. (See, kids, that’s why you should always keep the stub.)

But that’s closing the barn door very much after the coded horse has run off. What could Carl’s have done to keep these coupons from going accidentally viral, and how could they better have handled the error once it showed itself?

Shira Simmonds, president and co-founder of mobile coupon platform Ping Mobile—and not involved with the Carl’s Jr. promotion—says that coupon promotions for free anything need to be on the lookout for unwanted viral spread through discount aggregators and affiliate networks.

But even more, she adds, the campaign could have been controlled by getting rid of carbon-based couponing and restricting the offer to mobile coupons only. “The first step would have been to put it on the phone [using a platform such as Ping’s],” she says. “Then on the mobile phone we could have used unique coupon codes that would have prevented the offer from being forwarded to other recipients.”

Everyone who texted in to get the coupon would then have simply brought their phone to the restaurant and shown the text message with the code. Counter workers could have inserted the code from the SMS, validated it, and handed over the free grub.

Using a mobile coupon would even have given Carl’s an additional promo opportunity, Simmonds points out. “If someone tried to share the mobile coupon, servers could check it and say, ‘Sorry, this coupon has already been redeemed. But if you text the word ‘Junior’ you can get a free fries with your burger.’ That gives the other customers an incentive to stay in the restaurant and purchase.”

That’s got to work better than simply assuming all customers, including the 276 with legitimately obtained paper coupons, are guilty unless they can prove they were at the game.

To be fair, many store operators and franchisees of chains like Carl’s are more comfortable taking paper coupons. Their POS systems or their sales staff may not quite be up to the task of inputting codes or other data from customers’ phones, and being able to match slips of paper received against free burgers given out is an easy way to keep a handle on employee malfeasance.

And some marketers basically are willing to trade a certain number of Web-shared coupons for benefits such as increased store traffic and the sampling of new menu items. But the giveaway items have to be priced right. A retailer can afford to distribute a number of free 79-cent sundaes; putting the power of viral Web distribution under an offer of a free $2.75 hamburger can be a promotional disaster.

The lesson for today is that while it’s great to make friends with a coupon promotion, you’d better realize that those friends have other friends—and they don’t mind sharing.

California-based quick service chain Carl’s Jr. found that out last week when they ran a promotion at a Los Angeles Lakers basketball game offering a small group of contest winners a reasonable prize: the chance to get texted a code to input in a specific spot on the Lakers Web site that would let them access a printable coupon for a free Carl’s Jr. burger.

It all seemed manageable enough. The text only went out to 276 contest winners during that one Staples Center game with the New Orleans Hornets. (Don’t ask me what these 276 won to earn their prize, because I don’t know and can’t find out.) The page on the Lakers web site was only open for 48 hours, and the participating Carl’s stores were ready to accept the paper coupons.

And yet, and yet. A day after it kicked in, the promotion was cancelled, the Lakers Web page connected to the promotion was closed, and at least some of the Carl’s Jr. outlets were posting signs saying that the coupons would not be honored because they had been “seized from a secured Web site and distributed illegally.”

According to press reports, the promotion was halted after 50 redemptions. I’m not certain how 50 coupons from an expected redemptions pool of 276 tipped Carl’s or its parent CKE Restaurants that something had gone awry. Maybe someone presented a coupon in the 12 states other than California where Carl’s has outlets.

More likely, someone from the company or one of its agencies was monitoring the Web or just doing a Google search and saw that the limited-circulation coupon code was in fact making the rounds of the many, many Web sites focused on aggregating coupon deals and free stuff. Once released into the wild, the code just spread logarithmically. You can’t stop the march of free food across the Internet.

According to a blog report, Carl’s says it will still honor coupons from presenters who can show that they were actually at that Lakers-Hornets game. (See, kids, that’s why you should always keep the stub.)

But that’s closing the barn door very much after the coded horse has run off. What could Carl’s have done to keep these coupons from going accidentally viral, and how could they better have handled the error once it showed itself?

Shira Simmonds, president and co-founder of mobile coupon platform Ping Mobile—and not involved with the Carl’s Jr. promotion—says that coupon promotions for free anything need to be on the lookout for unwanted viral spread through discount aggregators and affiliate networks.

But even more, she adds, the campaign could have been controlled by getting rid of carbon-based couponing and restricting the offer to mobile coupons only. “The first step would have been to put it on the phone [using a platform such as Ping’s],” she says. “Then on the mobile phone we could have used unique coupon codes that would have prevented the offer from being forwarded to other recipients.”

Everyone who texted in to get the coupon would then have simply brought their phone to the restaurant and shown the text message with the code. Counter workers could have inserted the code from the SMS, validated it, and handed over the free grub.

Using a mobile coupon would even have given Carl’s an additional promo opportunity, Simmonds points out. “If someone tried to share the mobile coupon, servers could check it and say, ‘Sorry, this coupon has already been redeemed. But if you text the word ‘Junior’ you can get a free fries with your burger.’ That gives the other customers an incentive to stay in the restaurant and purchase.”

That’s got to work better than simply assuming all customers, including the 276 with legitimately obtained paper coupons, are guilty unless they can prove they were at the game.

To be fair, many store operators and franchisees of chains like Carl’s are more comfortable taking paper coupons. Their POS systems or their sales staff may not quite be up to the task of inputting codes or other data from customers’ phones, and being able to match slips of paper received against free burgers given out is an easy way to keep a handle on employee malfeasance.

And some marketers basically are willing to trade a certain number of Web-shared coupons for benefits such as increased store traffic and the sampling of new menu items. But the giveaway items have to be priced right. A retailer can afford to distribute a number of free 79-cent sundaes; putting the power of viral Web distribution under an offer of a free $2.75 hamburger can be a promotional disaster.