Comiket may be devoted primarily to fan-created doujinshi, but that doesn't mean you won't see plenty of official promotion for official series as well. Check out this gallery of a particular train station (the one nearest to Comiket's location, Tokyo Big Sight), which is practically wallpapered in posters and the like-- especially for manga and game series that have or will become anime series.
These are just a small selection, so make sure you check out the original article!
A Haruhi gag manga in which Yuki is a doujinshi fiend
CLAMP's upcoming anime Kobato.
Akikan!
Kuroshitsuji
Gundam 00
Man, I wonder how much it would cost to deck out a Portland MAX station like this...
While we're add it, I'm going to throw in this link to a really hot maid. Muwahahaha.
And that maid link? HAWT. Especially the matching shoes.