Television and movies both hew to the fact that our eyes are next to each other, not one over the other. A horizontal image more closely aligns with our natural field of vision. Yet the scourge that is vertically-shot video is not going away, and in fact appears to be gaining traction. As sad proof of this, advertisers are embracing portrait over landscape; and if they're sinking money into the format, that means it's working.
First off, why do people shoot vertically? The overwhelming assumption is that these people are idiots, but as designers we also understand the power of ergonomics. It's more natural to hold the phone vertically in one hand than horizontally with two hands. Couple that with people's inherent laziness and/or fear of dropping their expensive smartphone and this is what you get.
Secondly, who's watching vertical videos? Mobile users. Those of us on laptops and desktops hate watching vertically-shot videos since they don't take advantage of our screen orientation, but as more people shift to consuming content on their phone on networks like Snapchat, it makes more sense for them to watch a vertically-shot video that perfectly fits their device's screen.
And sadly, vertically-shot videos are proving profitable due to the ergonomics. "'Snapchatters' hold their phones vertically in their hands — the way that they typically use their phones," writes Jon Steinberg of the Daily Mail. "The whole notion of turning your phone on its side to watch a video is awkward and a bit of a hassle." And as advertisers have begun experimenting with portrait over landscape, "Snapchat has told us that vertical video ads have up to 9x more completed views than horizontal video ads. [Boldface and italics his.]
"Our findings," Steinberg concludes, "have convinced us that we need to move even more aggressively to develop vertical content, especially on our Snapchat Discover channel, and that our industry must develop creative content for this mobile format."