I'm sitting here in my hotel room in Perth after just having flown ATL-SFO-SYD-PER (and reading FT instead of figuring out what day it is or whether I should be sleeping now, but that's another story). The SFO-SYD 747 was maybe at most 1/4-1/3 full, and many of us in coach ended up with 3-4 seats per person. You can construct a pretty decent lie-flat bed with 4 middle coach seats and a pile of pillows and blankets! All in all, made for a most comfortable 15 hour flight. I just couldn't figure out how the airline was making any money on our flight, as the amount of fuel used to fly that far was surely not impacted too much by the mass of PAX and our bags, compared to the mass of the plane. Maybe there were lots of first and business class folks up front and up top making up for our light load in coach. I surely won't complain. With ATL as my home airport, I almost never fly on planes with empty seats - the gods were definitely smiling on me yesterday (or the day before). And best of all, the SYD-PER flight was the same way, so again I got 4 seats to myself. Was more self-conscious about lying down on that one though, as we were more in daylight.