Someone at work was looking to get to Europe later this summer and asked my advice for how I find cheap fares. I pointed out ITA in addition to my paid ExpertFlyer account. A quick search later turned up an Air France -marketed, Delta-operated flight that was significantly below the prices they had seen elsewhere.
They went ahead with booking, but overlooked that it was a Delta-operated rather than Air France-operated flight. Coincidentally, The Cranky Flier had a piece about the downsides of codeshares for passengers. I’m not that thrilled by them either. As United and Continental merge, I’m frequently placing bookings from one carrier operated by the other. Even as flight numbers shift around, the two haven’t been brought in line with each other. UA1 is a flight from Sao Paulo to Houston right now and CO1 is a flight from Houston to Guam via Honolulu.