In the world of Daybreakers, humans aren't normal, vampires are. The world has fallen into a plague where everyone craves blood and the human population is nearing zero.
This movie is good in the sense where being human isn't normal for society anymore so we see all the adaption to aid vampires live a normal life. Such as blood in the daily coffee drink, subway walkways that protect from the light and light mode in cars to protect from sunlight. It's an interesting vampire world! But humans aren't erased from the picture just yet, there are survivors. However in a world full of undead vampires that are farming humans for blood as though they were animals, surviving is harder than it sounds.
In a tale of good vampires, bad vampires and humans, blood is the key. If you're a vampire fanatic (and not the sappy sparkley ones) then this is definitely worth the buy!