"Diary Of A Wimpy Kid: Dog Days"
One of those franchises that you're only aware of if you have a kid (or have to look after one), the original "Diary Of A Wimpy Kid," which is based on a popular children's book, surprised many by opening to $22 million in March 2010, ensuring the immediate greenlight of a sequel. Diminishing returns had already set in by the time "Diary of A Wimpy Kid: Rodrick Rules" hit a year later: the opening was slightly bigger, but it closed out almost $10 million down on the original. The film's not an international power-house either, and with the third entry hitting in the tougher summer market, we'd be surprised if there was a fourth, even if these are cheap as chips to produce. Maybe they can add Dwayne Johnson next time around?

Percy Jackson

"Percy Jackson & The Olympians: Sea Of Monsters"
So it turns out that, somehow, "Percy Jackson & The Olympians: The Lightning Thief" managed to make $226 million worldwide when it hit theaters two years ago. Who knew? It wasn't exactly the 'Harry Potter' successor that Fox were hoping for (especially with franchise-launcher Chris Columbus at the helm), but given that the kids flick probably sold plentiful merchandise and DVDs, it's meant that they've pushed on with a follow-up. Clearly, cost cutting is the order of the day: "Diary of A Wimpy Kid" director Thor Freudenthal replaces Columbus at the helm, and in place of the first film's upper B-list supporting cast (Sean Bean, Pierce Brosnan, Uma Thurman, Catherine Keener, Steve Coogan, Rosario Dawson), we get... Missi Pyle and Mary Birdsong from "Reno 911." If you listen very carefully, you can hear the sound of a barrel being scraped.

"Grown Ups 2"
We have to admit, it's clear why Sony have greenlit a sequel to "Grown Ups," the Adam Sandler & his pals flick that functioned as a kind of "Big Chill" for people who were repeatedly dropped on their heads as babies. With a domestic take of $160 million, and an worldwide total of $260 million, it's the biggest global hit of Sandler's career. Even given that the original cost a ludicrous $80 million, and a sequel would surely top that, it'll make  a profit, so it's a smart decision. But the Sony executives are surely human beings. They have souls, and feel empathy, and give to charity. So how, in good conscience, can they greenlight another fart-joke-fuelled holiday for Sandler and his pals? Maybe we're giving them too much credit.