This afternoon, I got an email from USA3000 (a small carrier that serves the Caribbean from a handful of East Coast and Midwest cities), encouraging me to "Fly for $1 to Cancun or Punta Cana!" But when I investigated the offer using the "Flexible Traveler" feature on its website, I didn't find ANY $1 fares. The lowest price I saw was $99.
Now, USA3000 has offered this deal in the past, and it's always been worth taking a look at for at least a few cities. But in this case, it isn't worth your time. Maybe the $1 fares were extremely limited and sold out before I tried booking, but even so, I'm not sure why USA3000 would advertise prices that don't currently exist (other than to lure potential buyers seeking "a last minute gift for someone special"). But don't be fooled by this sale; just like Santa Claus, it doesn't exist.