Board Thread:News and Announcements/@comment-3544775-20131011210311/@comment-3544775-20131012162050

It pretty much depends on the show, if those you mentioned where longer running, they would have been with same success. There is simply no guarantee that if you create 4 seasons with 13 eps, that it will be more successful than making one 52 ep anime. One of the problems is that usually the long running like OP, Naruto, FT, Toriko, do not have bluray releases and currently majority of the shows that have bluray and dvd releases, the bluray outsells the dvd. People started preferring to buy blurays and those shows not having them, it hurts their sales at some extend. It also depends on how liked the show is and how well the merchandise sell. The publisher is more likely to want a long running anime, as it's better for them, so it would be up to the studio if they want to go to that road. It also depends on the budged of the studio, since an 52eps per year anime have bigger budged than 26eps anime (although per episode, the 26 ep anime have bigger budged).

Also it's more expensive to create such long running anime, and it also needs more chapters to animate, which is usually why most of the shows are shorter. Aside from that it must be popular too. So when the time is right for nanatsu anime, depending on it's popularity then, it may or may not get longer running anime.