Thanks for all the replies. A few more questions:

I have a few international trips coming up next summer (CFU & MHG). I'm worried that I won't be able to earn CO miles for these trips. If I want to earn CO miles, then I am required to book these trips through CO, correct? What if CO doesn't fly directly to my final destination, but only partially, then I should still book through CO and hope they offer me an affiliate airline for the final leg(s) of my trip, correct? (I assume that I would still get miles flying with a CO partner.) Now, what if the CO website gives me no results when I type in a destination (this happened when I typed in CFU)? Would I be SOL in terms of earning CO miles for this trip? What would you do?