... FX Networks in 2013 made the biggest off-network deal for The Simpsons library to air on FXX. The reruns have boosted FXX’s ratings. FX/FXX has one animated pilot in the works, a cop show from Louis C.K. and Albert Brooks, that is eyed for FXX. More animated development will follow as the efforts in that area will be stepped up. ...
That is not to say that FXX, which launched with FX’s biggest comedy hit, It’s Always Sunny In Philadelphia, is getting out of the live-action business, [FX Networks CEO John] Landgraf said. But animated content will be ramped up. “It’s one of the things that we excited about, it’s us taking new really big shots.”
Part of the rationale for the push — animated comedies attract the younger viewers that FXX is after.
The "attract younger viewers" strategy also explains why Netflix and Amazon are loading up with animated product. They want the eyeballs of pre-schoolers and elementary school kids to watch their brand and then graduate to live-action fare as they become teenagers and young adults.
It's the "catch 'em early and keep 'em" philosophy. I'm not sure it will work exactly as FX or Netflix or Amazon plan, but you can see what they're going for.