While many conference goers purchase the program, many do not and prefer to use the conference app. Even though I purchased the program, I glanced through it in a rush and never took the time to sit down and look at it. I did specifically look for the ad placed by my publisher, but aside from that, I never paid any attention to the ads themselves.
Keep in mind the conference is only four days and for most attendees it is four days of madness and rushing around. My program was still stashed in my bag until just before I posted to see who placed ads. If you're going to place one I would suggest a half page vertical ad. The reason being those are the only ads listed directly alongside the conference schedule since each pages is in a two-column layout. And since it's spiral bound, I would imagine many people might use it like I do and fold it back on itself, meaning if it's a full page ad or a horizontal half page ad (which would like be paired with another half page ad) those will be flipped past to get to the relevant material.
tl;dr: I think you're better off spending your money elsewhere.
