[Nyororin]

I think that a lot of people automatically assume that anime is hugely popular in Japan just because it`s *from* Japan.

It`s just another form of media. It really isn`t all that particularly special, really.
Normal people will watch an anime here or there, and read manga every once in a while.

Just like people will watch a soap opera here or there, or read a fashion magazine every once in a while.

Anime doesn`t take up much time on normal tv - sure, you can get an anime only channel via satellite or cable, but you can also get a 24 hour golf channel. It doesn`t mean everyone watches it.
On normal broadcast channels, series have one episode a week. Little little kiddie shows aren`t even usually on every day. It really is a very tiny percentage of programming, and anime "fans" are really a very very small percentage of the population. It`s silly to assume that fringe culture is mainstream - like cosplay, otaku, etc.

I`d say that anime and manga are no more popular that any other type of media.