Nick had little to no marketing for the return of Korra. After episodes leaked online in Spanish it seems the show was rushed on air. While on air, Korra was placed on a 7pm Friday night spot, which isn't bad, but there was no big lead up or reminders. The show just came back and fans were thrilled by the engaging new story and wonderful animation.
Whatever ratings it wasn't getting enough of, which doesn't matter, Nick has nothing in place for Fridays that will generate more.
If the executives at Nick can't sell a show so well-made with a huge fan base then they need to be fired.
For it to be airing digitally it only asks you to torrent it and not give any money to Nick and it's sponsors. By any means it makes no sense to put in online alone. It's new content and all networks face a lack of content. Airing new episodes could only generate more views of Nickelodeon, not less.
It's the same question asked for episodes of Beware the Batman on Cartoon Network. Why not just air the cartoon at a time when you would be showing reruns or poor ratings content to generate some more business?
This might be vented at Comic-Con between the show's creators and Nickelodeon at their own panel. Some fans could at least tell Nickelodeon off in it's misguided root. A fourth season has already been ordered by Nick.
