This week I used LOT Polish airlines from Warsaw to London with an offering of Business, Premium Economy and Economy on a Boeing 737. I remember LOT moving to BoB a few years back but they now offer 3-4 rows of premium economy on short haul for passengers paying more. It includes drinks and upgraded meals, priority boarding, etc, and seems to work well, particularly for frequent flyers.
BA could learn from this to enhance their model and customer satisfaction. And the evening meal tray in Premium Economy was good and very welcome.