I've heard the same about Micronesia - just because it seems so small a destination and far away doesn't mean there's not movement a lot of VFR, tourists, commerce, cargo, etc. I don't think CO would have had a seperate division (
Continental Micronesia, IATA: CS) if it wasn't profitable.
Some of these flights are the only means to the outside world besides travel by water. As stated in wiki, "[Continental Micronesia] was probably the single most important factor in the future development of what were once remote and isolated islands in the Pacific."
Interesting read about service to those islands. Also, correct me if I am wrong, but those Guam flights are packed with Japanese tourists and honeymooners - it's their version of our Bahamas or Cancun.
As another mentioned it's the routes where there's 5 airlines flying to/from the same cities that I find myself curious about - even if a flight is packed doesn't necessarily mean it's profitable. Like AKL-SYD...