their challenge is that the uptake at the front cabin is poor
On one of the few occasions where I was routed via United to Newark I enquired at check-in as to the possibility of upgrading to Business. The cost would have been £799, one-way, on top of the fare my company had already paid. I don't know what the going-rate for business class is but it's hard to see how that increment could be justified. Even if it had enabled me to work for seven hours it would still have been five times my salary for that period; by my rough maths you'd need to be earning £200k pa to justify it, at which point you're more likely to be flying in a bizjet or sending your staff.