One source reported it as a fare to Boston, I’ve also heard it was valid to Los Angeles. The airline says just over 100 tickets were purchased, though I’ve also heard 300. In any case, the airline currently says they won’t honor the tickets, though it doesn’t sound like all of this is final yet.
It’s highly unusual for a flight deal ultimately not to be honored. Hotel error rates are more hit or miss, but airfares are mostly good once ticketed. Occasionally an airline will back out, but even then I’ve frequently seen some sort of compensation given in return. So this will be an interesting one to watch.
(Thanks to reader Larry for the tip.)