The premiere averaged 4.5 million viewers ranking it as basic cable's number-one kids' show and top animated program for the week with total viewers. The Legend of Korra also ranks as the network's most-watched animated series premiere in three years. Book One: Air drew an average of 3.8 million viewers per episode. This was the highest audience total for an animated series in the United States in 2012. Book Two: Spirits premiered with 2.6 million viewers. Suggested explanations for the reduced number of broadcast viewers were: the long period between seasons, a change in time slot (Friday evening instead of Saturday morning), the increased availability of digital download services, and generally reduced ratings for the Nickelodeon channel. Book Three: Change aired on short notice in June 2014 after Spanish-language versions of some episodes were leaked on the Internet. Because of the rushed release, the season premiered with 1.5 million viewers. After declining TV ratings in the third season, Nickelodeon stopped airing the series on television and shifted its distribution to online outlets, where the show had proven to be much more successful.