I think it has everything to do with the movie itself.
Both Tangled and Wreck it Ralph became more and more popular as word got out and people saw the film or
video because they are good movies.
I think that movies like Lone Ranger and Oz, because they are live action, don't really lend themselves
as well to pins and so there aren't that many pins to begin with and people don't seem too crazy about the pins that were made anyway. POC is really the only live action film that seems to be of interest to pin collectors, unless I'm forgetting something. The live action Alice in Wonderland pins definitely have some popularity, but there's the animation crossover for that one.
The Marvel pins are always going to have some pin collectors go crazy for them because they have a
big fan base, so when the pins look great, like the new Iron Man ones, I think they will sell/trade well.
Planes is an interesting case. There wasn't much buzz or interest for the film or the pins
and unless you like that style, I don't think the characters are all that
appealing. (Haven't seen the film, tho) There doesn't seem to be any increase in interest like there was for WIR and Tangled.
Brave is interesting because there was lots of buzz (Pixar film, Princess, Themes, etc.) so there was
initial interest. But I don't think the interest in Brave fizzled. It seems like
there is still high interest and demand for those pins, and they keep making more
Frozen has buzz and interest. Unless the movie is terrible, I think those pins will be really hot,
especially since it always seems to take Disney a while to realize what there is
high demand for. I mean, there still aren't really that many WIR pins, but
people really want them. I think it's going to be the same with Frozen.