The problem with some of McF's newer licenses is shelf life. Napoleon Dynamite was hot for what, six months?
It was everywhere and you could find anything with ND on it (shirts, keychains, notebooks, etc.).
Items that can be easily turned around from a manufacturing standpoint - take a blank keychain, stamp the ND logo on it and you're done.
The problem with figures is that they take A LOT longer to develop. Investment is actualy required. You need skilled artisans to make the tooling models, then you have to cut the steel molds, run first shots off of the molds, tweak the molds, advise the paint ops, obtain licensor approval...all of this takes close to a year from start to seeing the product on the shelf.
More often than not, by the time the product is in production, the trend is over.
Remember the chopper (Jesse James) craze a couple years ago?