Well, that was a surprise. JetBlue, seemingly out of nowhere, announced a bid for Spirit. JetBlue's offer of $3.6 billion is $700 million more than what Frontier offered and could derail Frontier's bid. At first, the industry reacted with shock — no one saw it coming. But as the dust settled, the deal started to make sense. After all, it would allow JetBlue to acquire more (and compatible) aircraft and grow into a worthy competitor to the Big Four airlines. But the flip side is that JetBlue-Spirit isn't as obvious a combination as the tie up between two ULCCS like Frontier-Spirit.