A poster speaks for itself; the presence of its author is not necessary. It is therefore possible to reach a broader audience when compared to a presentation limited in time.
It is also possible to present several posters in the same room and at the same time; visitors can have a look at those posters they are interested in.
Sometimes as the author you have the possibility to present a poster while giving a short introduction. An interactive situation evolves while having a close contact to the audience, closer than when delivering a speech.
Posters can be used several times and presented at different events.
A poster is suited for people suffering from stage fright at least, for those who have difficulties when speaking in front of large groups. Standing next to their poster for some time in order to answer just a few questions is less stressful than talking on a lectern.
Poster can be used several times.
Once a poster is printed it will be difficult to make corrections or adaptions; it is therefore less flexible when compared to a presentation that can be modified any time.
A poster must attract attention. Especially when being presented at a poster fair, it has to compete with many others posters.
Preparing a poster can take just as much time as when writing a speech. However, practice makes perfect.
Posters generally require reduced content as well as getting to the point. Selecting what has to be included or omitted is not always easy.
What is printed is printed; it is therefore necessary to thoroughly check for errors!
If choosing between delivering a presentation and presenting a poster (a lot of congresses offer both possibilities), one should consider which form of presentation is best for one's project before preparing things accordingly.
Those with a creative vein can achieve a great deal with a poster.