Originally Posted by
jrc+
United says that they don't have any "Premium Economy" and that "Economy Plus" is an add-on option to an Economy ticket, not a cabin.
That is correct.
I have experienced the same and since Economy Plus with UA is not a class in it's own you cannot book it as such - you can do that online on united.com afterwards though, but it will cost those 59,- (depending on route). It is well worth to purchase though if you have a significant leg length.