That's fine at the flyer table. Anything beyond that ...
I, personally, would not want someone actively trying to hand out flyers in con space. And I don't want random surfaces covered in random flyers.
Jaki gets final say on this (or Beau, if he pokes he head in), but I don't see a way besides the flyer table to make advertising unobtrustive. I just don't want congoers always bombarded by ads. Partially, because if *we* need to be promoting, advertising or informing for some reason, I don't want it drown out. Last year we made lots of signs for two events, because they were not in the con book so people had no other way of knowing about them.
Last year, for the Ouran panel, they sent hosts out to talk to people about the panel to spark interest. And that was fine, as they were not yelling or, from what I could see, being agressive. Also, people have used the forums to spark interest in panels and events as well.