Why Horizontal Scrolling Makes Sense For Instagram
“With the horizontal feed, each photo (and each ad) is given the spotlight at any given time — you can only view a single post, and the comments are much more prominent now, appearing with a flick upward.
It’s also much harder to quickly fly through your feed with the new layout: you can only advance a single post at a time.”
It is no secret that a lack of ad inventory is a significant threat to the financial growth of Facebook and Instagram. For years, the changes we have seen with Facebook represent the company toeing the line between increasing ad inventory without running off its users.
Within Instagram, Stories has outperformed timeline posts in engagement for a couple of years. With an opportunity to increase engagement - with both ads (making advertisers happy) and organic posts (an arguably-good litmus test for user experience) - and increase ad inventory, this had to be an absolute no-brainer inside the Facebook offices.