Board Thread:Questions and Answers/@comment-25222488-20150227031543/@comment-6697950-20150302215659

Filler arcs are done for series like Naruto where the anime releases episodes at such a speed that the original material needs time to progress the actual story. SAO is not that kind of series. It barely has any filler that wasn't part of the original medium. The Extra Edition is probably the only longer and more notable original footage. Other than that and another scene or two, the SAO anime mostly just sticks to animating existing content, not making up new one. Heck, it's doing better at omitting content than creating new content. And yet people still watch it, so doesn't that mean that it's still interesting despite not having any surprises for those who read the original material?