I would venture to say the $29 routes are not profitable. However, that in itself may not be a true reflection of the value of the route. First, some routes are always going to be more profitable than others. Its just the way things go. Next, if travellers on this route are typically part of a connection to elsewhere in the network, there is more revenue coming from PIT pax, just not a lot of PIT-JFK traffic. Finally, until the plane is actually needed for a more profitable route, and as long as its not losing money or drastically impacting overall company profitability, its probably around to stay.