Every one knows that LoK was delete from iTunes Store at some period, but within less than 24 hours of Korra’s triumphant return to iTunes, both books 3 and 4 are already in the Top 10! At the moment 3rd book is at second position and 4th book at the tenth. Also 2 book place on twentyth and 1 book on twenty fourth positions. Therefore all four books of LoK make a top 25 list of TV Shows in iTunes Store.
I am from Russia and we haven't opportunity to buy and watch LoK officially therefore I specially restered an account at the American iTunes Store, bought a gift card (I haven't american credit card) and bought several series of third and fourth books, also I rated all books and wrote reviwes.
If someone has the opportunity to some support the work of the founders I strongly advise to do it. Thanks for your attention.
P.S. sorry for my English.