This is compared to the standard 23-24 minutes per TV series episode. The most popular show I've heard of with this format is Hetalia:Axis Powers. A comedy anime series about the various stereotypes of nations around the world. Personified into cute Anime characters. Episodes are only 5 minutes long. I've never watched it but it does seem to have a strong online fan following. Chii's Sweet Home being another show and episodes only run for 3 minutes. I believe the show is about the life of a cat.