Dan,
If I was in the boutique film business (Classicpan, Efke/Adox, Forte, Foma, Lucky etc), I would not waste my money buying an ad in the mainstream photo magazine. I am changing career's into public relations after years in retailing, sales and marketing couple that with my obsession with this hobby.
I would buy banner space on APUG, Rangefinder Forum, Camera Collector and link it to my website. I would write features and pitch the story to the magazines and maybe show up at events like the APUG conference and sell the film at an agressive price to build interest. I would also give away rolls of film to what I would term opinion leaders and let them play with the film, if they like what they use, you have your spokespersons in place.
Viral and marketing public relations for a small boutique business makes way more sense than buying a full page advert in Pop Photo.