At least on EWR transcon they are severly underserving the demand for FC. I understand that their fleet is stretched to the max with their int'l expansion, but I would have to imagine that it would be in their interest to increase the FC cabins of their 738's to 24 seats, thus replacing the lowest-yield Y seats with much higher yield F passengers. There would also be a commensurate drop in payload not to mention a legion of much happier OP elites.