It could be that the social information increased the probability that someone noticed the banner or that it increased the probability that someone who noticed the banner actually voted or both.
Kungenzeka ukuthi ukwaziswa social anda ematfuba ukuthi umuntu waphawula banner noma ngicabange ukuthi belivele anda ematfuba ukuthi umuntu waphawula banner empeleni bavotela noma kokubili.