Show your card? why would you ever need to show your card at the gate? Blue has no value whatsoever besides earning miles and if you book online you usually have your number in it anyway.
All I am pointing out is that there must be many millions of blue members who never use the card, these members cost BA money.
I also paid for my gold myself without any company travel so I know the crack of the whip.
Getting back to the original topic... some weeks ago I ha a thread about the additional perks I'd like to see for gold, some of those would fit nicely into an additional level.