The Anime News Network is reporting that sales of downloadable books (primarily manga) over mobile phone networks grew by 331% in Japan in 2006, and totaled more than $14 million.  At the same time Internet sales of books grew 67% and totaled $68 million.  The Digital Content Association of Japan projects that mobile phone sales of e-books will mushroom to $99 million in 2007 surpassing Internet downloads, which are projected to finish this year around the $80 million mark.

The rapidly increasing sales of mobile and Internet downloads of manga have been cited as the primary reason behind the recent downturn of manga sales in Japan  (see 'Production IG Merges With Mag Garden').