SHUPirate1: You could not be more correct in your closing sentences "...does codesharing...actually help the airline? In my opinion it doesn't..."
It is sheer folly for airlines to imagine that they are helped by codesharing when they
share/divvy up the same fare with another airline when they could have
and would have captured the same revenue (albeit from a different passenger with a different destination) by keeping the passenger online (airlinespeak for one's own airline) and keeping 100% of the ticket base fare revenue. It should be a no-brainer, but as none other than Gordon Bethune has stated, "this (the airline industry) is a stupid business run by stupid people."
Here's an example to illustrate. My airline can fly you from
SEA to
BOS on our flight numbers in one of two ways for the same fare. From
SEA via
ORD on a connecting flight with our codeshare partner -- or non-stop. Since it can be reasonably assumed that our codeshare partner will not carry our passneger on the
ORD-
BOS leg for free, we have forfeited about half of the revunue we could have had had the pax flown on our non-stop
SEA-
BOS flight. Plus, the fare
SEA-
ORD (typically 80-90% of of our
SEA-
BOS fare) that we couldn't sell because it was occupied by the
BOS bound pax was also lost. All of which is a textbook case of serious revenue dilution -- when the whole issue of losses in spite of load factors at record high levels comes down mostly to a revenue issue! We would have carried just as many
SEA-
ORD pax and our
SEA-
BOS non-stop would have carried the same load factor -- and, between the two flights, we would have kept
100% of a considerably larger base fare revenue pie.
And the issue of costs is by no means helped by codesharing (and costs, along with weak and diluted revenue, is the other factor keeping airlines in the red in spite of strong load factors). It is costly enough for one airline to deal with its own issues on a day-to-day basis. It becomes considerably more costly when it becomes necessary to deal with the service issues of a codeshare partner in addition -- even while revenues are being diluted in the process. Which is the double-whammy incurred by code-shares:
real revenue (what the airline gets to keep) goes down while costs go up.
In conclusion, except for some of the confusion caused for pax (like "who do I check-in with?") and the possibility of getting "caught in the middle" between two airlines (represented as one in codeshares) determined to pass the proverbial buck when customer service issues arise, codesharing is great for pax; it does not in any way help an airline. Those who would have us believe otherwise are simply proving the veracity of Gordon Bethune's view of the industry and those who (mis)manage it.
As empirical evidence for whether codesharing
really help airlines, take a look around. Is it the airlines who are totally immersed into codesharing who are losing big $$$ or is it the airline who lack such "helpful" arrangements?