Till Chaptering Do Us Part

What do the film adaptions of the Harry Potter books, the Twilight books and the The Hunger Games books have in common? Yes, they are all film adaptions, smart-arse. But apart from that, their respective final part has been split up for cinema. Sure, later books in a series may tend to becoming longer and longer due to an expanding universe, and at least the first aspect (becoming longer) is the case with all three tales. Yet one cannot but consider a certain money grab-ish side within this practice.