Brian Barrett, writing for Wired, with a behind the scenes look at Netflix:
The instant Daredevil premiered, Netflix greeted its users with eight header image variations of Matt Murdock and friends, shown to customers in eight identically sized chunks. Netflix immediately began tracking which top shots inspired the most streaming.
By now, those eight images will have given way to the best-performing two or three. After 35 days, one of those will become the default. The rest will vanish. This happens now for every Netflix original show. It’s survival of the clickest, all around the world.