Facebook has added carousel advertising to mobile after nearly a year on desktop. Carousel advertising is one ad that has up to 5 sub ads to scroll through.
According to Facebook, carousel link ads drive 30-50% lower cost-per-conversion and 20-30% lower cost-per-click than single-image link ads. The key is to create a story between the ads to entice viewers to want to scroll rather than a row of ads. With all the advertising we are constantly bombarded with, a well-done carousel ad will make users want to interact and interaction means additional attention.
Instagram also offers carousel ads. Click here to see a demo video.