A travel agency or tour operator has a finite marketing budget and has finite capacity to advertise its products. There will be some potential customers its advertising won't reach. Aircraft have a fixed number of seats and while in peak season those seats can all be sold, there will be inevitably some empty seats in low season, however good the pricing policy may be.
A travel agency / tour operator based in (e.g. Inverness) chartering weekly flights over the summer season between Inverness and Rome will likely focus its advertising in Inverness. A person in Rome who wishes to fly from Rome to Inverness and back (e.g. to visit Loch Ness) may know from the Inverness airport or Rome airport websites that there are charter flights between Inverness and Rome and also know the name of the airline doing the flying, but not have any idea as to which travel agency is chartering those. Google doesn't always come up with the answer to everything.
Yes, some of those flights may be full.... but perhaps not all of them, particularly outside the peak season. Person in Rome is happy to pay money for non-stop air transport, and travel agency in Inverness will usually happily take money (i.e. negotiate a price) for selling empty seats outside peak season.
Thus there is sometimes a genuine good reason (modest, but not zero) for the charter airline to disclose the name of the travel agency. The counter-argument is that if financial risk is borne solely by the travel agency, then the charter airline will (in the short term) prefer to operate a flight relatively empty as it reduces their operational costs - less weight, less fuel, etc...
I don't expect a charter airline to disclose which seats have remaining capacity - but I would expect a reputable charter airline to disclose the number of the travel agency / tour operator when it's available to the mass public, so the person in Rome can at least ask the travel agency whether they might sell a ticket when there are empty seats
A travel agency chartering a whole aircraft might want to structure the fees so that a *very small* - maybe 2% of revenues - bit of the financial risk is borne by the airline - this would encourage the charter airline to promote the flights on its website (i.e. very cheap to do) and also ensure the airline gains an active reward in the airline being viewed well on Internet review sites.
Last edited by davidjohnson6; 10th May 2022 at 14:13.