When a website makes a mistaken offer which customers then accept, contracts may very well result. However, that is only a small part of the story. The mistake may mean that there really is no contract. Or the website’s terms and conditions may protect them (though there are some situations in which such terms might not be enforceable).

This kind of mistake is a pretty regular occurrence, and it happened to United Airlines over the weekend. Via the Gulliver blog on the Economist website, I learn of the following story in the Chicago Tribune:

United Airlines error sells Hong Kong flights for 4 miles

United Airlines customers with reward miles were able to book tickets over the weekend to Hong Kong for only four miles, plus taxes and fees, because of a programing error, according to the airline.

A round-trip flight from Los Angeles to Hong Kong typically starts around $1,800 or 60,000 reward miles under the MileagePlus reward program.

But because of a programing error, some United passengers who booked flights to, from or through Hong Kong were charged only four miles plus taxes and fees, which amount to about $35. …

United Airlines have cancelled the tickets, though it is not clear to me that this is permitted in Rule 5 of United’s Contract of Carriage (and it may run afoul of the US Department of Transportation rules). I have blogged about similar mistakes on the part of Aer Lingus, Dell, Best Buy, Arnotts, and Round Hall, but I never cease to be astonished not only at the number of websites selling goods and services which do not provide for these kinds of mistakes in their terms and conditions but also at the widespread apathy there is on the part of consumers for these terms and conditions.

For me, the moral of these stories is clear. Vendors should ensure that the terms and conditions of their websites cover such eventualities; and consumers should be aware of such terms and conditions. Here, as in so many other situations, the real issue is that, in the words of too many annoying advertisments, terms and conditions apply. And since they do, consumers should be aware of them.