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Join Date: Sep 2012
Location: SFO
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The reason for not overselling J is that pissing off passengers who pay a premium is perceived to be horrible for business.
As such, if J is full, I would except that they would not oversell PY (though I'd be curious to hear if they have).
But if there are 5 seats free in J, I see no reason why they wouldn't oversell PY by 5, knowing that they're going to be doing e/op ups.