no no no no no no no no NO!
If I may step in to C3's defense (cherish the moment, it will be rare!!!), let me try to rationalize C3's choice for the A330.
1. They already operated the A320, so that commonality is an issue.
2. At the time of them making a decision, the acquisition costs of a new A330 and a new 767 would probably be very close.
3. The operating costs are not that different from an A330 to a 767-300ER. However, with more seats, the revenue earning potential is greater, and even more so when you consider the cargo capacity as well.
4. New aircraft, and therefore launch customer discounts.
5. It fits with the C3 "elite" moto, as they have a brand new aircraft, while the competition (Transat, Royal) were operating "old" aircraft. Passengers surely appreciate sitting in a quiet, clean and new airplane. They are also very roomy aircraft compared to other charter aircraft.
So ... costs not much different compared to a 767, both to acquire and to operate, greater revenue potential, and customer preference.
I am also very sure that they often operated the thing completely full, on Lisbon and London flights in the summer, and I wouldn't be surprised on Cancun and Vegas flights in the winter. So all in all, going back to their time, and sitting in the board room with them, and given the information they had, it probably wasn't such a bad choice.
Oh, and another thing, C3 was a charter at the time. The tour operators wanted available seats, and C3 made their money regardless of 50% or 100% loads. It was not their responsibility to sell the seats. And remember as well, there were very strong rumours that when C3 was going sched, they wanted 767's. So then they surely knew that the 767 was more in tune with what they needed for their sched services, as opposed to the A330's. Some food for thought for all of you, sorry for the length of this post!
"it's kind of like an Airbus, it's an engineering marvel, but there's no sense of passion" -- J. Clarkson re: Coxster