Posters are popular because they are cheap and compact, both for the presenters and (more importantly) for the conference. Posters are usually used in high-vol

Posters are popular because they are cheap and compact, both for the presenters and (more importantly) for the conference. Posters are usually used in high-volume settings with very light review. "Everybody" attending the conference gets to present a poster if they want to. > a video... an interactive computer screen Now you need 500 monitors at the conference venue, power cables, etc. The costs add up big time; hotels make a killing on this type of thing. > a talk You want to limit the number of talks so that the accepted talks are actually well-attended! So, not everyone gets to give a talk. Also, most people who give talks also present a poster because maybe there was a parallel session that stole some of your audience (who are interested enough to find you at the poster session). At least in CS, no one is choosing a poster over a talk! talks are reserved for the work that passed the highest bar of peer review this year. (That said, I always recommend people present posters for some of the reasons described below. Even though talks are "higher status", IMO posters are often more effective once people are engaged.) > a demonstration These are sometimes rolled into poster sessions, but require more space and planning on the part of the organizers. Space at conferences is often hard to find. > an interactive exhibit, a diorama, a play This is kinda funny coming from a CS/math background. I guess in some fields this could make sense but would have the same drawbacks as videos or talks, respectively.