Twitter is looking to provide advertisers with more options to maximize their video ad campaigns, with a new 15-second view bid unit, which will prioritize reach to users who are more likely to consume video content. 

As explained by Twitter:

“To better meet the needs of advertisers who rely heavily on quality video views and video completion
rates, we’re rolling out a ‘15-second (15s) view’ buying model that prioritizes for engaged, longform views on their content. This new bid unit is built to optimize for delivering 15-second or completed views, whichever comes first, and early testing has shown that it drives Twitter’s highest video completion rates yet.”