Originally Posted by Trusty

Well, for premium economy they could use the same seat as in economy or the same seat as in business.
This would be more flexible to organise.

the difference between premium and economy or premium and business would be just service on board, service on ground, miles and probably price

OR actually they could have both: economy plus and business minus
So one can choose: economy seat with service (on plane and ground) as in business or business seat with service (on plane and ground) as in economy