IANAMAAM (I am not a Madison Avenue advertising man) but advertising film would seem to have two potential goals. One is to reach existing film shooters and convince us that a hypothetical Kodak Quad-X is better than everything else out there and we should be shooting it. As mentioned above, there are not that many of us, and not any good centralized places to advertise to reach this audience. You also run the risk of cannibalizing hour other products if you oversell the benefits of your new product.
The second goal would be to get non-film shooters to shoot film. Again, I don't have any market research, but there are not many areas where there is potential growth. Former film shooters that have a camera in the closet? Maybe, but that doesn't sound like a customer that hangs around. You might make some nostalgia sales, but if they have a camera and don't know they can get film in it, they aren't very dedicated, and they don't seem to have the dedication and passion to be a recurring customer.
More possible growth areas seem to be pro/enthusiast digital shooters. They already spend a lot of digital gear. The are very into photography. Getting them to consider film as a hobby next to their digital gear seems to have potential. You see writers on the various photo industry blogs that fit this mould. The are primarily digital shooters, but like shooting film now and a gain as well. You may look at them as poseurs that shoot film so they can feel artsy, but that doesn't matter, as long as their interest is genuine.
There may also be the "hipster" crowd (sorry, I hat the term, but..) If I had to guess, it seems like they are bored with the digital revolution (not just photography, but all aspects of digital.) An they are more enamored of things that feel "real." They were raised entirely in the digital world, they've had Facebook since at least junior high, and they can't disconnect, but they want parts of their life to feel less ephemeral. (again this is a guess, based on a very small sample set.) What ever you think of their opinions, they are genuinely held, though I wonder how permanent they are. None the less, they are a potential growth area. I have no idea where to reach them, but I do know that they don't read magazines. I assume online somewhere, because they grew up online, and can't really leave.
Are there other markets out there where new customers can be found in enough number to justify advertising?
(As an aside, I just watched an old--maybe 5 year old--episode of Futurama in which Bender, the loud mouth, booze swilling robot, was film photography aficionado. He had a full darkroom inside himself, and the climax of the episode was that even though the Professor had destroyed the photo, since it was shot on film, Bender could reprint it from the negative. So maybe film has a future...)