Originally Posted by PremiumSeat
...(although United is eliminating all F service to and from SJU in 2006 --- TED all the way -
). ...
There's your answer. SJU, along with CUN and probably AUA, are considered "low-yield" routes (not that the fares necessarily reflect that). jetBlue, Spirit and TED have made their mark in SJU. US balances that by providing tons of lift (up to 5 flights a day from PHL on weekends, including the A330 and 767).