The incremental cost to Kodak of giving away 100' of movie film to an individual is almost entirely related to the cost of fulfilling the request. The film itself costs them almost nothing. In return they achieve a one-to-one contact with someone who at the very least will end up being favourably impressed with Kodak.
They would have to pay a lot more for other types of marketing capable of achieving the same result.
The fact that the OP intends to re-purpose the movie film doesn't really detract from that marketing benefit. The extra difficulty involved in the re-purposing effort also means that the availability of a free sample like this doesn't markedly reduce the market for the full price product intended for still photography.
Over here when Kodak introduced new films they gave out request forms at least to commercial photographers for sample films.
Originally Posted by Valerie
At the introduction of Ektar 100 at Photokina they gave 1 sample away to those who showed interest.
Kodak and other film manufacturers used to give films away at trade shows I used to go to like Chinamen with no hands.
Before the rise of digital it was common for photographic magazines in the UK such as Amateur Photographer to give away free rolls of film, usually Kodak colour neg or slide or Ilford B&W, attached to the covers of their magazines. It usually happened every few months. There was nothing to stop someone buying several copies as often the magazine price was less than the normal retail cost of the film!
Sample E100g converted my dad temporarily back to Kodak slides
I once emailed them asking if they'd send me a JUCO Portra postcard and after they asked me what I was doing with them, I got a dozen
25 years ago, it certainly was not uncommon for Kodak to give away some film to student filmmakers (especially for festival shorts, and sometimes even features). Often times you didn't get a full ten minute real as you were getting "left overs" from a run, but trust me, you made do with whatever you could get your hands on.