Blue Sky, the United and JetBlue partnership just announced, will give frequent fliers more ways to earn and use miles.

A new Blue Sky agreement, as the two airlines are calling it, will allow United to fly out of New York’s JFK Airport once ...

Rivals can—and in the show do—try to dye their inferior goods, but adding food coloring to white meth doesn’t reproduce the distinctive color of Blue Sky. And by the same token, any dilution ...