With company policies changing a lot in recent years regarding business travel, WTP is becoming a more valuable solution for carriers. Indeed, I often wonder why there aren't more PE seats on planes, as the cabins are rather small (helps drive up the price, I s'pose).

Also: WTP will seem better when economy is further downgraded with additional seats being crammed in, more HBO flyers scattered around asking to swap seats in order to sit together, etc. I wouldn't be surprised if, eventually, BA ditches long-haul free booze too (AA doesn't offer spirits for free, for example, it's at a charge), which would save a chunk of outgoing costs for the carrier.