Also, (was this covered before?) it's important to note about upgrades from WTP -> Club,
as every time there is a WTP sale over the past few months many people get disappointed .. always look at the fare basis to know whether that WTP fare is upgradable.
You can identify it by looking at the fare basis calculation, after the amount it says NKW3G4T1 /KW7G4T1 . This is the "fare basis". The first letter indicates N (or K) - which means it's an economy fare in reality. Premium economy fares will start with T, E or W and those are upgradeable.
Happy new year,
Daniel