When setting up a Video view campaign, what's the default buy flow, and what is its performance benefit?

The default is multi-format, and it can drive up views and consideration lift. A Video view campaign serves across in-stream, in-feed and Shorts by default, letting the system place the ad wherever a quality view is most likely for each person rather than restricting it to one surface. That flexibility is what improves results: different people watch in different contexts, and multi-format delivery usually produces more views for the same budget than a single-format buy, with corresponding gains in consideration. The practical requirement is creative variety. Multi-format only works properly if assets exist in the orientations each surface needs, so vertical and square versions matter alongside the horizontal cut. Restricting delivery to one format should be a deliberate decision with a reason behind it, not the starting point.