>>117153793Avatar's ratings in the first 13 episodes were way better than anything else they had tried, so they just renewed everything till the end if I recall. The Blue Spirit would've been the series finale if they hadn't renewed them, think about that.
Hard to remember a time when a show only got more and more ratings by the 3rd season, and this is despite a massive gap between season 2 and 3 AND a massive gap in the middle of season 3. Finale broke so many damn records. Unfortunatetly, they haven't been able to recapture that magic, even Korra went straight down in ratings.
