It's very clear to me why CO has the BF policy that it does. I fly to Asia once every month, and to London twice a month. On virtually every flight, there is someone who was on the waitlist but didn't get cleared for one of the few BF seats that are set aside as reward seats. Time after time, I see these folks whip out their credit card and pay thousands of dollars for one of the unsold BF seats. If CO were to set aside more BF reward seats, they would see those last-minute revenue upgrades cease. On my flight to NRT last week, they sold at least 3 (that I saw) and maybe even more were sold after I boarded. I don't know how true it is, but a redcoat I spoke with said his friend in revenue management told him that on all CO BF flights, there are a minimum of 3 seats set aside as reward seats, and a maximum of 6, on a 777.